Just a little word of warning, the GTX480, while being a very potent card, will need very good cooling and a lot of power.
If you do not have enough power (a powersupply with enough wattage) it will not start at all or not function right. Might even be damaged.
If you do not have enough cooling, you risk actually frying the card. It easily gets up over 100 degrees celcius, constantly working right at the limit of the parts it is buildt from. nVidia is also having problems with their silicone wafers, and they tend to come apart if exposed to a lot of heat over a long time period, it happened to my GTX275 this spring after I had it for a few months (my current GTX470 was a replacement I paid a bit extra for).
It is also extremely loud, like a vacuum cleaner.
I chose the GTX470 because it uses a little less power and thereby creates a little less heat. I had to send it into service (most likely) because of overheating, even though I had the mobo-bay of my Tt Level 10 case open with a table fan running at full blast cooling it down during the summer.
The 460 is a new generation that has a lot less problems (not a 480 with parts disabled like the 470). It should run the game very well.
IF you have a good PSU and a very efficiently cooled case a 480 would provide considerably better performance of course.
While I've been an nVidia fan since 1999, unless you want to use the 3D Vision stuff like me, I'd almost recommend an AMD/ATi card if you want to get the absolute top-of-the-line cards...
