After upgrading the firmware on my board to the SS BIOS, it looks like it supports an 850MHz cpu. I've heard people have managed to put a PIII 1GHz cpu on their board.
I'll upgrade to the P3-850 as soon as Intel decides to drop the price to under $100. For what a P3-850 is going for right now, I could get a new mobo, spend another $50 or so, and go AMD at over a gig.