Do the milkshake the milkshake do the shake
Ubisoft has offered no reason for bringing the game forward, but we're not going to argue. Given that this game was never ever meant to arrive on PC (with developers complaining about "bitching" fans), we're happy with what we've got. And, for that matter, it's a nicely PC-enhanced version, complete with extra gameplay modes, rather than being a simple console port.
Jimmy the Geek