It was already cracked two weeks before release! From a few days ago on Buzz:
Just saw a post on the Steam Forum for Assassin's Creed 2 that the impossible to beat, always online, can't save your game or even play the stupid thing without being connected to the internet DRM for it has already been cracked 2 weeks before its release. sigh Did Ubisoft really expect this to work any better than previous attempts to crack down on piracy? Now what they're left with is a piece of software which is being pirated just as much as any other game, except that it treats its legitimate buyers like they're suddenly going to turn into pirates after they've already bought the game.