Just some points on your spec how I see shadow... and im talking from a pure PvE PoV...
Disc Tree T2
Martydom - If you get crit from a raid boss you won't be alive to use the effect and even if you didn't die you wont survive remaining hits to use it's ability either. Apart from that why would you want to continue dps if you pulled aggro, the idea is to stop dps and let the tank establish threat. This talent is a pure PvP talent and as such I wouldn't bother with it.
Silent Resolve - You wont cast enough holy spells for the threat reduction to mean squat and i'm unware of any raid encounters that dispel your dots. As such I don't see what value you can get from this talent.
Because the other talents do nothing you might as well pick up Imp PW:S, its not great but it's of more benefit than your other options. Self casting PW:S has it's uses in PvE and the imp version may keep you alive.
For 1 point i'd pick up Inner focus, it has a decent MP/5 equivalency and now that crit is going to be useful for us, getting 25% more crit on MB every 3 mins isn't going to be awful. It also allows for quicker wipe protection or putting up a prayer of Fort when you don't want to spend the mana.
You pretty much have all the talents i'd take... except I don't agree with not taking dispersion. It's gonna be a great 'oh shit' button to avoid death and it's going to give you some nice mp/5 if required for all of 1 talent point. Ask yourself what the MP/5 value of 1 point in vieled shadows is when you compare it to dispersion... 36% max mana is going to be > than 1 min off your fiend.
It's going to be a bit subjective atm, but how important is VE going to be in the new environment? VE was really nice in SWP for TBC, so I wonder if that passive healing is going to be desired in WotLK? Maybe not early on but spending 2 points in Imp VE might be something you really want to consider depending on the content you're doing.
With Meditation, Inner Focus, Dispersion, how necessary is 3min fiend going to be? Sure it's nice to have but the fact you dont have Imp SF makes me feel that spending 2 points in this talent isn't min/maxing the best you could.
The spec has all the core abilities but I do think you sell yourself a bit short with no dispersion. Half the battle in most end game raid boss encounters is staying alive, particularly while people learn so you can clear it quicker. Like I said above it has to have a higher mp/5 value than 1 point in vieled shadows anyways so why wouldn't you take it? I guess it's a personal choice thing but I don't see why that spec couldn't dps just as hard as any other possible spec. My choice of talents is below:
Just some quick points on how i might change it
1. I'd look to steal a point out of shadow affinity if threat becomes a non issue, i've heard conflicting reports but we do get 30% threat reduction from SF alone so stealing 1 point might be possible.
2. There was some talk about switching Imp Inner Fire with Imp PW:S, if so that would give us another 3 points to spend in the shadow tree (not sure it will happen but there was talk). If that happens i'd take Imp VE & 1 point in vieled shadows.
3. If the tree stays the same, i'd probably look at stealing points out of Imp Inner fire if it becomes apparent that imp ve is needed, or imp SF, or vieled shadows. Keep in mind that each point in imp inner fire is only worth 18 spellpower so it's not a huge loss and the ability to provide healing, reduce pushback or get more mp/5 would well offset that loss.
Items i'm sure people will disagree with
1. Dispersion - Sorry, 1 point for huge mp/5 and 90% damage reduction is too useful for it's cost
2. 5/5 Imp MB, if you want to utilise haste to it's max benefit you need to reduce the CD as much as possible. MB is still the highest DPS spell we can cast and as such the mroe you can cast it the higher your dps. If this wasn't the case you'd bench it out of the cycle and just MF spam.
3. Imp PW:S, I agree this is somewhat crappy but what else can you take? Maybe 3/5 Unbreakable will but that is likely to have less use than Imp PW:S imo... perhaps it will be content contingent.
I think everyone is likely to agree with the other talents.
I think Veiled Shadows may end up being a must given the reported mana problems SP's are having.
It should be entirely possible to take one point out of Pain and Suffering and never lose your SW:P- 18 secs up, even on a bad rotation where you recast VE, VT, DP, MB, SW (which as of now isn't worth casting in raids) including cast times and global cooldowns, you're at 9 seconds- that still leaves 3 mindflays, with ANY haste at all you get a 4th cast off with a chance to refresh. Again, it's not 100% and it would really suck to lose SW:P, but I think you can do this and still be safe.
As of now, Inner Fire isn't worth having for PvE. The 60 extra spell damage you get is a pathetic damage boost. The extra armor for PvP could be argued to be worth it, but as a PvE spell it's a waste of a spot.
dont think imp inner fire is gonner be worth it. whith all the random aoe damage (and having shorter range on MF) i think imp shadow form is gonner be better off then alot of other things, remimber not losing ticks on it is gonner inc youre mana per damage alot :]
this is my version but on the other side im gonner spec holy so
Spell pushback is being changed to a max of 1 second which is vastly different to what it is now... in addition even if you reduce the amount of pushback you receive your channeled MF is still going to lose a tick...
As for high end content... I can only think of 1 encounters where pushback is a realy problem, that being RoS in BT. It's nice to have for some other encounters but I don't believe any other encounter has a significant negative impact on dps.
If WotLK content proves to provide significant pushback issues, i'd take it... but at this stage i'm taking an educated guess that pushback isn't going to be a real issue, particularly with suffering a maximum of 1 second additional cast time.