... Think bigger than the group environment though, for a second. The trend to focus on single-player wants and desires (i.e. gear, personal Xbox Live style achievements) is what has atomized the game and completely annihilated the 'Massive' part of 'MMO'. Yes, you can still play in an insular group of personal friends in parties and never notice the harmful effects that cross-realm and LFG has had on your gameplay experience - but really? The best thing about Vanilla - in my opinion - was the sense of community on each server (especially before the Battlegroups, as well). Idling in a capitol city you'd get to 'know' so many people by their name/gear/guild alone - a real sense of a pecking order, certain guilds having reputations (good and bad). Most importantly, a real tangible and overall sense of server progression (events like AQ gates were a masterstroke in MMO experience). Nowadays the server you play on is pretty irrelevant. I really miss that feeling of knowing certain guilds and groups of players just from sheer familiarity alone. The same with battlegrounds: getting to know other players on the opposite faction, as well as PvP guilds, and knowing when someone was 'skilled' and infamous, etc. That really contributed to an awesome, epic feeling to the game... which has been shattered and lost now. Everybody basically playing a solo version of the game where the sole occupation is getting over 9000 achievement points, or farming epic-gear tokens in random LFG. It sounds like a cliché complaint, repeated certainly ad absurdum... but clichés exist and gain prominence for a reason (i.e. they contain at least an iota of truth). If WoW wants to regain its stride and pick itself back up into that early feeling where everybody was buzzing to play it, they'll certainly need to try and reintroduce a real sense of community cohesion in Mists of Pandaria.
Of course the sad truth at the end of the day is that there is absolutely zero financial incentive to do so such a thing. And with WoW Gen 2 in the development pipeline I really doubt they'll ever be so bold as to try and revive their company cash-cow's fundamental strengths.