A good, three-part interview with Tim Sweeney (the other FPS graphics guru):
Part 1: http://www.tgdaily.com/content/view/36390/118/
Part 2: http://www.tgdaily.com/content/view/36410/118/
Part 3: http://www.tgdaily.com/content/view/36436/118/
His main thesis is that soon GPUs will be come so programmable that you won't bother using a standard Graphics API to program them. You'll just fire up a C compiler.
I think he's right.