It's not perfect, but it's a huge improvement on the 'give us all your money and we'll allow to play our new game, in certain conditions, when we feel like it' DRM.
I wouldn't be surprised if there was a huge spike in sales, and I'd be even less surprised if the suits at Ubisoft DON'T put 2 and 2 together and realise that the DRM was stopping legit customers from buying.
I so nearly bought AC2 in the steam sale but couldn't support a company that wanted to tell me when and how I can play my (sorry, ubisoft, your game, I know I'm only throwing money at you for the chance to occasionally get access to it) game.
If they'd done this 2 weeks ago, they'd have got a few thousand more sales I'm sure, because of the Steam Sale.
also, are not about 90% of full price sales of a new title completed in the first couple of weeks after release? Why wait nine months? Three would be excessive, but...meh, ok. Nine is just dragging your heels.