Registered just to post this line:
SOLD!
I need a workstation-class machine for development, but like to do gaming as well. iMac'12 just does not cut it, even pimped out one (mine also got screen ghosting, thank you Apple).
And instead of spending extra $2K to get a decent gaming rig (not mentioning space, cabling and general messiness) I can just get dual D700s.
Well done, Apple!
EDIT: I think 6-core Xeon would be faster, due to higher clocks and the fact that games do not need lots of cores usually, too hard to develop for. And proper gaming drivers add even more speed of course.