Oh wow my bad. I thought you had to simply activate your game...it has to be authenticated every time you start it? That's harsh...
It makes little difference to me personally though. I would think most people who would play AC2 are probably always connected to the internet, but it's a shame...
http://www.amazon.com/Assassins-Creed-2-Pc/dp/B001TOQ8R0/ref=sr_1_3?ie=UTF8&s=videogames&qid=1264470862&sr=8-3
According to Kotaku, AC2 is supposed to cost $60 on PC, "justified" by the inclusion of DLC which costs money for console gamers.
But, Amazon still has the preorder available for $46.99