i dunno first hand either.
i have read a few articles that say the new 2.0ghz opty (1212 santa ana) is capable of 2.9+ on stock voltage.
abit makes a good board for it, NF-M2.
if i was to go opty i would probably try the am2...it's about 200.00 on the egg...it would be great to have one and push the o.c. ability. plus you have am3 coming out sometime, maybe Q3?
but then again, the durability and the reliability if the s939 is impressive. it's just that you have no upgrade with that platform. though, granted...with a good vid card and plenty of ram a new s939 opty build will last for a couple of years, probably.