<|Premise|>
For raiders and dungeon crawlers (the majority of warcrafters) you'll still be stuck afk'ing in cities waiting on queues and lockout timers. PvP'ers pretty much as well.
You want people out in the world, there needs to be an incentive for these people that is just as strong as going to these instances. There needs to be a unique currency in the open world and competitive rewards monetized by it. Remember, not everyone likes pokemon and not everyone is interested in growing plants, although it's cool that it's there for those people. However, adding those things to the game don't add much for raiders, dungeon crawlers and PvP'ers:
PvE
- Instead of instancing scenarios they could have made it open world and then adding a switch to make any scenario anywhere "heroic" boosting the difficulty to end game.
- Non-instanced very big and long open world dungeons ( they used to do this )
- Open World Bosses ( they got a few of these )
- Open World PvE currency needs to be exclusive from other currencies as well as having its own exclusive and competitive gear.
Edit: Stopping Exploitation in open world PvE
5 man open world dungeons could have multiple entrances with CDs on those entry points, there is a timer on how long the group has inside the dungeon. Raids cannot enter. Open world bosses can either A) give a buff to the primary raid group that started the encounter to stop them instantly dying from an AE attack or B) balance the boss to have a ton of players participate with individual loot distributed amongst the participants.
PvP
- Open world PvP simply needs its own currency and competitive exclusive rewards, maybe even the top PvP weapons could only be bought with open world PvP currency
- Open world PvP areas: now it failed last time because the rewards sucked, they didn't have lockouts so factions constantly switched unopposed areas meaning people just take another while the other faction occupies the other etc etc. Open world PvP areas with lockouts, once you take the area many elite guards will be there making it impossible for "x" amount of time and they will despawn, this makes sure each PvP area gets used and circulates players around the world.
- Owning a PvP area streams resources to your faction distributed amongst player characters, every "x" minutes/hour(s) you are streamed in game currencies, owning more PvP areas accumulates more streamed currencies per "x" minutes/hour(s).
- Killing unique players in succession yields higher point gains, with repeatable world pvp achievements by killing players in certain ways can up your rank increasing yield and lost if you die to another player. I.e. kill 25 players get the slayer rank and buff etc Getting an extremely high succession of kills will mark you on the opposing factions world map and a bounty will be placed on your head, you cannot ride flying mounts with this bounty.
- Leader board ranking for daily, weekly and monthly pvp kills and achievements earned etc etc.
- Also aside from offline measures which Blizzard should enact to balance servers, underdog features should be introduced to help including but not limited to, a bolstering buff similar to that of WG, a 3rd rogue faction that will attack the current occupant in addition the to opposing faction, stealth/guerilla warfare type skills specific to the world pvp area like bombs booby traps, temporary stealth devices usable in combat etc etc.
Edit: Stopping Exploitation in open world PvP
As mention before there are lockouts likely to be 24 hours resetting at a specific hour on a server's peak time, the majority of open world PvP points come from these open world PvP areas, which have faction wide benefits. Kill trading will be discouraged by diminishing returns. Engaging in world PvP will put a 10 minute debuff on you that will disable use of flying mounts. You can go to major towns and cities to remove this debuff for gold.
For PvP these changes aren't very difficult to apply it's just another competitive loot table, currency and giving world PvP areas (that don't already have them) lockouts, places like TB and Wintergrasp need to be made bigger and have their instancing removed with legit tools/strategies created for underdog factions. Creating open world end game PvE content for scenario's might need some work but it is essentially setting up a triggered event with a switch on it, 2 things that already exist in the game. So overall, all of the tech is all there, these simple changes would in fact bring people out in the world PERMANENTLY.
Enjoy MoP being the same pony trick Cata was.
Edit: The main point is to have people out and about in the world, although yes we can come up with a myriad of solutions for exploitation and imbalance, the main focus is that PEOPLE WILL GO OUTSIDE AND NOT AFK IN CITIES. Which the above would duly accomplish. To conclude, don't post if you're simply going to say something won't work, it is not constructive to point out a problem and not add a possible/plausible solution/remedy. Go back to 9gag if you want to be captain obvious or Sherlock Holmes. This is not to be construed with me not wanting "negative" feedback, no this is me not wanting useless feedback.
I.e. "This rocket needs way more fuel than the current pipping can allow, yeah it will fail." Yeah no shit, think of a way to increase it rather than just point it out. If unanimously the scientists came to the conclusion that there is no feasible solution in the universe, then and only then you can say it will fail. Derp.