Don't you feel your current card is adequate for gaming?
I would say, keep your current card for a little while. it should play all the games decently at that resolution
I wanted to switch cards with my HTPC because I couldn't get the HDMI working on the ATI with my TV, so I figured I would put the Nvidia with component output in my HTPC and that worked. Just wanted to make sure I wasn't sacrificing anything with graphics performance.