Well, to give you an idea I actually have the older (better) version of the GTX 460 with the 256bit memory bus. I play games like Civilization 5, Warhammer: Space Marine, Total War: Shogun 2, and quite a few older games on either high settings or ultra with no AA filtering at 1920x1080. That being said though, I'm actually in the process of ordering parts for a new build because I feel like my card is not going to keep me at that same level of graphics quality in near future releases.
So, if you plan on sticking with older/less graphically intense games, the card will take care of you no problem. Future graphically intense releases in the next year or so? You're probably looking at "normal" settings for your graphics.