From what I know, Ubisoft's
Prince of Persia (2008)
didn't have any DRM at all, yet the sales were still good. Bit strange that Ubisoft went from that into this DRM craze 'n' hacked servers phenomenon.
On an actual note, I've been thinking about buying AC2. Internet connection is not a problem, but the news about the Ubisoft servers being down are keeping me from deciding for the purchase. Then again, people also say that they experienced no problems with AC2, except the occasional server downtime, and that there are certain times of the day when such problems do not occur.
So I'll say that what's really keeping me from buying it is that I've recently bought GMod, and I'm reserved from buying 2 games in the same month. Commence stone throwing now.