Elmer, I fully expect Prescott will match Opteron on single processor benchmarks, at least in 32-bit mode. However, Prescott is still hampered by that shared bus, so it will have problems due to scaling limitations. There is just so much you can do with cache for 2-way, 4-way and higher systems.
Just as PCI made EISA, ISA and MCA bus systems look old (and took Intel to a new level), aHT is an elegant architecture which is making all previous PC busses look old.
So I agree that Prescott will be very impressive internally. All AMD has to do is deliver on the technology which they now own and Xeon platforms will quite literally be last year's technology.