A few issues will need to be addressed with TBC

[satella]

In 2.4.3, Horde had racial advantage.
2.3.0 brought with it a number of changes to alliance racials.
Fear Ward from ( 30s CD for Dwarf/Draenie ) -> ( 180s CD for ALL priests )
Escape Artist from ( 60s CD) -> (105s CD )
Blind no longer considered a poison (Stoneform can't remove)
Dwarves held up the Alliance on their shoulders, but if Blizzard is going to use 2.4.3 as a template, anyone with forethought (who doesn't care about looks/lore) will decide Horde is better for PvP overall. On PvE servers, the problem won't really be noticeable, but as most people choose PvP servers, most people will go horde.

Another big issue is how they're going to handle those that didn't play Classic, but now want to play TBC.
Having the option to play on a fresh server is absolutely essential for those people, along with the many who just want a clean slate. If private servers are any indication, it's that people really like that fresh feeling, no matter how many times they've had to restart. Like having a nice cozy shower after a hard day at work.

I say option here, because of course they're not going to eliminate all the hard work of those that have played Classic since its inception. They should be rewarded for their efforts with easy leveling in T3 gear, along with keeping their character names etc. Anyone with the stamina and resilience to level a Draenei/Blood Elf in the pre-patch, deserves every advantage.
Capping gold might be a good idea, along with only allowing you to keep essential BoP items, perhaps there are essential non-BoP items as well that I don't know about.

There are problaby a lot of other issues (please mention them), but these seem like the most important to me.

[Kazer]

I have a feeling blizzard will treat it similar to retail, the existing servers will simply carry on to TBC.
The caveat will be they will also be launching fresh severs for Classic at the same time for those that want a fresh start or do not want to play TBC, you said this in your OP, I am just reiterating and agreeing with you.
My hope is prior to a TBC launch they will look at server balance and merge some of them to help imbalances. I don't think they will actually do this, but they should.

[Kralljin]

Racials:
I think they are beyond salvation, there is no easy fix.
Horde is already ahead in PvE because they have Command (5% Pet damage), Blood fury gives Spelldamage in TBC as well and Berserking is obviously fairly decent for any non tank.

Meanwhile, Alliance held some advantage in Classic due to Paladins and Human melee being extremely flexible in their weapon choice (Mace / Sword spec).
Paladin advantage is obviously gone and since weapon skills got nerfed in TBC and then reworked in 2.4 to Expertise, those racials aren't as good anymore.

Aside from that, you have Heroic Presence from Draenei (1% Hit), that's it.

Then there is Seal of Blood, which just seals the deal.

If you want racials to be brought into a reasonable state, they need to rework them heavily, anything else is just a baindaid solution.

Fresh servers:
Generally not opposed to that, but i think they will be rather unpopular because a lot more people want to keep their characters and due to WoW being a social game, you play where your friends play.
And people who haven't played Classic or have no interest to level a character for TBC, won't do it either way, at least not a huge number of players.
Those people rather have 58 pre mades, but that's another beast entirely.

Economy:
I'm generally open to any concept that somehow wants close off the Classic from the TBC economy, but that will heavily depend on the way they roll out TBC servers.
If they go for a completely authentic transition, it will be a shitshow.

[satella]

...And people who haven't played Classic or have no interest to level a character for TBC, won't do it either way...

People who haven't played Classic OR have no interest to level a character for TBC?
You are obviously unaware of the massive amount of people currently unsubbed (some since WotLK) who will only sub for TBC. I'm quite sure 90%+ of those would want a fresh TBC server. You obviously don't interact with them on forums or in game, so why would you be aware?

Premades are a very bad idea on fresh servers. On established servers, they might be good to alleviate some imbalance for Draenei/Blood Elves, but even then, having a long pre-patch solves that problem. Overall, premades are not a good idea.

[Schattenlied]

I have a feeling blizzard will treat it similar to retail, the existing servers will simply carry on to TBC.
The caveat will be they will also be launching fresh severs for Classic at the same time for those that want a fresh start or do not want to play TBC, you said this in your

That would be a terrible idea... They should just leave classic as is and let people copy over their characters to TBC... If they are going to force characters into TBC then they need to copy account data over to the new classic servers first else people will flip their shit, myself included. I didn't level 3 60s on classic only for Blizzard to take them away.

[kranur]

Allow for copy to the same servers as everyone, even those starting fresh. Maybe put a cap on the amount of gold copied or just don't allow gold copy at all.

T3 and bis vanilla gear with just allow some people to be heroic ready faster, which won't be that fast anyway because they need to grind revered, by which point everyone will have the same gear level, t3 people or fresh.

TBC is a continuation of vanilla and not a standalone thing. May as well only have access to outland if you are so desperate about fresh.

Economy will turn into a shitshow anyway.

[Kralljin]

People who haven't played Classic OR have no interest to level a character for TBC?

My post is kinda poorly worded in hindsight.

Point is that there are people who haven't played Classic at all, have an interest in TBC but do not want to level a character in Classic solely for TBC.

You are obviously unaware of the massive amount of people currently unsubbed (some since WotLK) who will only sub for TBC. I'm quite sure 90%+ of those would want a fresh TBC server. You obviously don't interact with them on forums or in game, so why would you be aware?

I'm not saying they're nonexistent, i'm saying that i'm not sure that there are enough to populate a server, as this server has no pre established players like any TBC server would where you can take your characters from Classic with you.

And if you have friends who have played Classic, you will have a much harder time to convince them to start over from 0 when they could just start with TBC right off the bat with the character they've been playing in Classic.

[Belloc]

My dream for a Classic version of TBC would be to follow the major milestones for patch releases. Skip the 3 or 4 different versions of Nightbane that we had over the course of a week or two and just give us the final version. I can take or leave the original Shane of Aran. Skip to the fixed Gruul and Magtheridon. Skip ALL of the original SSC/TK tunings and give us killable versions of every fight from the beginning. I would also prefer that SSC and TK be available at release, just like in TBC, but I can understand delaying them since the original versions were unfinished, untuned, and broken and only one or two guilds ever really got to see them in that state, and it would help pad out the game cycle.

BT and Hyjal were solid from the start, so they can follow the regular milestone patch cycle there. Same with ZA and Sunwell.

[Cæli]

Merge Classic and TBC? bwahahahaha

[Heathy]

I think t5 would exist at the start because the ssc attunement is in slave pens? it was gated by the attunement anyway not to mention you kinda need a frost resist tank and a nature resist tank for hydross so that will take a bit of time to achieve on top of the attunements and farming t4. since classic released on its final balance patch before the tbc pre-patch it would probably end up being the same for tbc, the final patch before wrath. but a lot of boss fights were nerfed by that point, illidan lost shear like mid way through. kael's adds were nerfed by a considerable amount. etc. I could see t6 and ZA being in a phase and sunwell being in the final phase obviously. but the game could probably start with t4 and t5 and last 6 months like that before t6. 3 months of that then sunwell for 3-6, I dunno if tbc can be stretched out for 2 years. maybe 1.5. wrath seems more like the expansion that could spend a year doing t7 and t8 and a year doing t9 and t10. but tbc I don't think it had the same run time as classic or wrath where it could be spread out over 2yrs.

there was 3? pvp seasons, so it means you could just have 3 phases, t4/5 phase 1 season 1, t6/zulaman phase 2 season 2, sunwell phase 3 season 3. I didn't do much arena i played a priest and I did a few 5v5's and 2v2s but i just found it a bit cancerous pvp in general as a cloth healer you just spend most of you time being ganked so it never appealed to me that much. it would probably make more sense to keep the pvp gear behind the pve gear in terms of best attainable ilvl should come from pve at any given phase.

[Mazza]

Aside from that, you have Heroic Presence from Draenei (1% Hit), that's it.

To devalue that even more, the class that arguably benefits most from +hit (rogues) can't even be Dranei.

[Kralljin]

To devalue that even more, the class that arguably benefits most from +hit (rogues) can't even be Dranei.

It's an Aura for your group, so that wouldn't be an issue, though the Draenei player had to be a Melee class, as Caster draenei granted Spellhit.

[deenman]

I have a feeling blizzard will treat it similar to retail, the existing servers will simply carry on to TBC.
The caveat will be they will also be launching fresh severs for Classic at the same time for those that want a fresh start or do not want to play TBC, you said this in your OP, I am just reiterating and agreeing with you.
My hope is prior to a TBC launch they will look at server balance and merge some of them to help imbalances. I don't think they will actually do this, but they should.

no way will they forcefuly take people to tbc,the point of classic servers was for vanila,getting tbc is just an extra bonus,the only rational way i see them doing this is to give you ptr like copy option when tbc launches or simply fresh tbc,and classic stays as is regardless

also OP some of those choices are not mutualy exclusive...we can get pre or post 2.3 and/or copy characters

[RobertMugabe]

I don't think that TBC is gonna be too unbalanced. The reason why is simply that all of the content is gonna be extremely easy (for different reasons) regardless, so it's not really gonna matter for most people which faction they're on. But yeah, in PVP I'd say the Horde will have a significant advantage and ALL remaining "balanced" PVP servers will shift to the Horde drastically, while those that were Alliance or Horde dominated will remain as to what they are right now.

All in all, we will just sorta have to deal with it. Classic is really just all about bringing back older versions of WoW and trying to keep as close as possible to how it was originally. Don't expect these Classic versions to be ever really taken seriously for balance and competitive gameplay.

As for the release of TBC: I guess the easiest option to manage for Blizzard and the easiest for most players to understand would be if they simply progressed the current classic servers into TBC and somewhere later opened up a few new classic realms. The other options sound good on paper, but they will be a nightmare to properly manage and will require some steps to follow for each player (ideally there should always be 0 steps required in these situations, since people are dumb or cba to read up).

[Insaniam]

That would be a terrible idea... They should just leave classic as is and let people copy over their characters to TBC...

Carrying current servers on to TBC and allowing character copies/transfers to a couple vanilla-only realms would be the best option. It's just simpler on Blizzard's end and simpler for most players. I doubt they're going to do anything without having the 1.13 option after all of this.

[Mysterymask]

Everytime i see threads like this i kinda laugh a little

Blizz bring back old expansions...
No not like that

[satella]

also OP some of those choices are not mutualy exclusive...we can get pre or post 2.3 and/or copy characters

It's multiple choice dude.

[deenman]

It's multiple choice dude.

facepalm....my bad

[Hinastorm]

I'm not interested in BC if this meta of "Clear the new raid/raids in 2 weeks tops, then farm them for 6 months while we arbitrarily wait for the next raid to open, gathering more and more BiS, thus ensuring the cycle continues" thing keeps happening.

Like, it's baffling that people keep playing classic like this, to me. What's the point. I would do like a 2 months on, 4 months off kind of playstyle if I could, but guilds understandably kinda want you to keep showing up to keep your spot.

[CerealLord]

The way I see it happening will be that players will be given two options:

1. Leave your character as is on the Classic server it is on
2. Transfer your character to the BC server at level 60. Allow all items to copy over.

They will then allow new characters, of course, to be created on that server and probably a few "fresh" servers without copy ability. It is the only way to appease everyone.