Yes, I just found this on the Geekbench 2.0 Results page. I checked the motherboard stats and they are the same as the 2009 model Mac Pro. This is a Hackintosh (somebody has dropped two 6-core X5680 chips in a 2009 model Mac Pro) and it worked!!! Geekbench 2 Scored a whopping 28239!! Holy *****! This is amazing!! The second fastest machine on Geekbench next to a 64-core server. In comparison, a 2.92GHz 8-core Mac Pro scores about 18000. This is a HUGE speed improvement. So, it can be done. The chips can be put in there, and the machine can be boosted to a dual 6-core. It works. Check this out::
http://browse.geekbench.ca/geekbench2/view/264312
http://browse.geekbench.ca/geekbench2/view/264312