We are a tad late reporting the first reviews of Radeon 9600 Pro boards, though our forum members had posted such links as soon as those went up (another reason you may want to keep an eye on the boards). Anyway, the new 9600 Pro is being clocked at an impressive 400/600 MHz (core/memory) in order to compensate for half the pixel pipelines that were left out in this mid-priced model (4 versus 8 found in 9500 Pros and higher end boards). Reviews here, here & here.
Results turned up as expected, the Radeon 9600 Pro managed to beat the GeForceFX 5600 Ultra in pretty much all tests by small margins and used to keep up a tad behind the 'older' 9500 Pro in most tests with the exception of AA and Anisotropic scenarios where the 9500 was able to show its muscle.
Now, one may think overclocking was not a possibility having the already high clock speeds but HardOCP proved us wrong, at least using their reference board they were able to clock the card up to 567/617 MHz using the stock cooler, an even more impressive mark for ATI's 0.13u, RV350 core.
I still believe the 9500 Pro is a better buy, at least while they are available, you can check prices and places to buy here.