Here's a great article by Tom's Hardware (may be worth a sticky) that breaks down performance in SW:TOR with a bunch of different setups and settings. Their analysis is basically that you can get the game looking nice with smooth fps but it takes a beefier rig than it probably should.
Judging by their findings you may actually even be slightly hampered by your CPU in addition to GPU...
I will say that, after reading this article, I decided to upgrade my GPU to a 560ti, while keeping my Core 2 Duo 2.66ghz CPU and 4 gigs of Ram. I play with all the settings maxed, but with Vsync on (I get a lot of tearing without it) I'm still getting less than buttery smooth fps in some outdoor and heavily populated areas. Nothing unplayable, mind you, but it's noticeable.
Here's hoping Bioware does some optimization to improve performance - I don't even have AA forced. Going to try it tonight but hoping it doesn't hit my fps too hard.