The GeForce 8800 GS option for the new Penryn iMac is a welcome addition -- especially for 3D OpenGL apps like games. At 1920x1200 High Quality on the 24" iMac, it doubles the frame rates for most games.
But if you are using it for Core Image based Pro Apps, as you can see from the iMaginator graph, it won't provide much of a gain if any. That may change as driver improvements are made. If so, we'll pass on the good news.
Stay tuned for some additional tests where we stress the CPU.
WAIT -- THERE's MORE
Some of you asked for comparisons to older iMacs. We're adding some results at 1280x800 High Quality that will give you a flavor of how they compare to the newest Penryn iMacs.