I have a 6950 2gb GPU and the only time I get a drop in FPS is on the fleet. I'm running at 1920x1080 res and in the rest of the game it sits between 80-110. In the fleet it can drop as low as 30 fps, depending on where I am in the fleet. I've found it starts to stutter around the lift to the Flashpoints, even if there is no one else around at the time.
But I've had many conversations with people in general chat about the FPS issues and it seems to be both Nvidea and Radeon cards that have issues.