Check out this video interview between Destructoid and Blizzard.
He confirmed that they are indeed calling the game Titan (their internal codename), that people weren't supposed to know about it ("the media's not supposed to know anything about that, it's our Next-Gen MMO"), and that it has been used quietly ("limited") within the organization.
In the beginning of the video, Destructoid was obviously referring to the recent leaked release schedule, and Frank Pearce cracked a big smile. =]
So - I think that's pretty much a confirmation that the release schedule was indeed legitimate. The release dates are all estimates of course (ie, setting a general roadmap for the company) and the actual release dates will fall short of their original goals based on trends, but at least they give us a really good idea of when they want to release the games even though our own estimates were pretty close. Unfortunately, this also means that all of that other critical financial and subscriber information is out there in the wild too!
Blizzard recently stated that they intended to develop smaller expansion packs so that they could release them much sooner - giving that release schedule more legitimacy (ie, one year apart versus every two years.)
