Assuming you could even get it to boot, I doubt you really want to do this long-term.
The 9228's thermal management hardware is a little quirky (two sets of fans split between two an ADT7470 and an ADT7462), and without proper OS support you run the risk of exceeding the thermal envelope pretty quick when the machine's under heavy load. While I haven't tried OS X on it, I do know this from experience with other, incorrectly-configured OSs.
There's also the matter of the RAID card -- since that's never been used in a Mac, I can't imagine that OS X ships with drivers for it.
I disabled the SAS RAID card, I use standard SATA HD's now. I have no use for SAS, besides the 15k RPM drives were really noisy. But thanks for the info regarding the thermal management. I guess I'll stick with trying to run it in vmware.