Bottom line is that there is probably not much reason to wait for the
939s. If quality is a real concern then you probably want an Opteron
system anyway. The 939 boards are going to be optimized for price not
quality, 940 boards are server class boards, 939s are consumer class.

Yes and great memory performance in 939 for consumer class since its
supposed to have two memory controllers like the opteron and FX:

http://www.anandtech.com/cpu/showdoc.html?i=1884&p=10

5315MB/sec memory bandwidth and lowest latency ever.