Apparently the rules don't apply to Blizzard like they do to everybody else. They've got a huge cash cow with WoW which gives them basically unlimited money and time to develop whatever games they want in whatever time frame they want. They also can bank on past successes, and know that they basically have a captive audience for whatever they release whenever they release it. If this was any other company, they would have had the game done a long time ago, and it would have been just fine. Plenty of companies release games in a timely fashion and they are not buggy, unfinished messes.
My only concern is that "early 2012" turns into "mid 2012" or even "late 2012," and then we will only have a few months to play what looks to be an awesome game before Armageddon. I can't believe more companies aren't taking this ultimate looming deadline into account.