For the new Mac Pros follow this thread:
http://duc.digidesign.com/showthread.php?t=280454
The new machines appear to be working, but there were two people who mentioned problems. I usually have to weigh their feedback against how technically inclined they seem to be.
I will be posting my results in this thread as well.
Also there are some additional factors to consider but the thread will cover them as well.
Hope this helps...