It's easy to get excited or disappointed about announcements for shiny new features (or the lack there of) but when it comes time to pop open the box (figuratively speaking) and get to playing, what makes the game enjoyable for you?
The Leveling experience?
If Warlords of Draenor exceeds expectations with it's leveling experience from 90 to 100 (which would not be difficult to do given the already very low expectation for leveling in WoW in general) then this xpac would be off to a very good start. With the lack of new classes or races to captivate us through to the endgame, will a poor leveling experience put you off the game before you even get started? Will a great experience have you logging/boosting alts?
Glorious dungeon design?
It has been a while since dungeon grouping has been a draw in WoW. I, for one, enjoy the dynamic of 5 man instances and the immersion that great dungeons can add to a zone/story line. Would a spectacular dungeon encounter fire up your WoD lust and give you high hopes for what the end game will hold? Are relevant dungeon runs a thing of the past for you and nothing more than achieve hubs nowadays?
PvP?
It seems that much attention has been paid to PvP in this upcoming expansion. An entire island will exist full of unending combat between horde and alliance with staging areas, combat hubs and all the shiney vendors and portals PvPers could want. New ways of getting and interacting with PvP gear also promise to address many issues players have complained about for quite some time. Would a spot on brilliant PvP experience send you off hailing Warlords as the greatest xpac Blizzard ever released? Would a complete fail send you raging on the forums?
Raid content?
'Get me to the endgame' has been the mantra of WoW players for the better part of a decade. New faces, new stories, new toys are always a big part of an expansion, but when the hours have been logged, the grinding has been done, and the blinders come on, are you all about boss machanics, raid movement and epic loot drops? Would terribly designed boss encounters put you off of your WoW sub until Naga in Space is released in 7.0? Would a truly epic raid tier keep you and your friends glued to your keybinds for the duration?
Game play/Class play?
Lost in the shuffle of output from most hype machines are the basics of any rpg... is the game or character fun to play? Whether you spend your time counting down at the arena gate, icing your skull from banging your head against a raid tier, or get your kicks inhaling the fog of war in every corner of the world, the way your character functions is a huge part of all of it. Would a negative change to your main spec have you rerolling Wild Star with Ghostcrawler? Could a small tweek to your class have you falling in love with your abilities again and carry you through every aspect of the Warcraft experience?
What floats your boat MMO-Forums?
[This would have been a poll, but I spilled some newb sauce on myself and just can't seem to get it to come out...]