I'd give WoW2 a shot, but only if they made some big improvements, including:
- player collision
- crosshair targeting
- friendly fire
- multiple personal story decisions instead of grinding bars to the maximum - more situations like Aldor vs. Scryer
- interesting story
- less races and classes, more depth, flavor and customization
Same continents and worlds + new ones, only this time, they are more according to scale and released over time, like in TESO.
Set in the past or future, for new story lines.
A fresh take on all features which often receive criticism, like raids and gear treadmills.
An entirely new WarCraft RTS, on the same scale as StarCraft 2.
Story lines which converge with and grow from old, current, and future WoW story lines.
Massive focus on eSports-worthy online multiplayer gaming.
Why isn't there an option for both? Blizzard is more than capable of hiring more developers and artists and anything else required and in fact they have done so for Wow which is an 8 year old mmo and that team is bigger than the team for Titan which isn't even out yet.
Oh and before anyone jumps down my throat, the OP asked what our preference was and mine is I want Blizzard to do both.
Warcraft IV, but i think that we wont see it until they finish with SC2, they already say that they only have one RTS team, and they´re working on SC II: Legacy of the Void, and it wont surprise me if they do a expansion for SC II after that. So, all that means...4-5 years until WC4 can really be considered?
I always think that WC4 doesn´t mean the end of WoW, it can be a parallel history, and their consecuences can be reflected on a future WoW expansion.
Of what i´m totally sure is that we won´t see a WoW 2, it doesn´t make any sense, they´re improving the game with every patch, i´m sure that most of the people want a WoW 2 for revamped graphics, but they can do that with the WoW that we now, a new Cataclysm will be the perfect oportunity to do it, and i´m pretty sure that we will see that sooner or later (both: a new ''Cataclysm'' or event with significant consecuences which include revamped Northrend and Outland, and new graphics).
Honestly I don't think either are likely or necessary, at least for a long time. Warcraft is more popular than it's ever been with WoW, no need to make it compete with Starcraft and risk alienating most of it's current fans (RPG fans).