I need to buy a new computer now, so I'm looking at the Mac Pros. I've been waiting since April, following the rumors, but I just can't wait anymore. Now, I used to do a lot of hardware stuff back when the first Pentiums were around, but I haven't educated myself in any of the newest hardware technologies, so.... Before I purchase one though, I had a couple questions: Do all of the Mac Pros have the same motherboard and chipset? Does this mean that if I buy the 2.8GHz Quad-Core Intel Xeon Nehalem, I could eventually upgrade to the Two 2.93GHz 6-Core Intel Xeon Westmere like the server model uses? As for graphics, am I pretty much stuck with ATI? And are the 5770/5870's the only options I have when it comes to a dual-card setup? I also read somewhere that it's not possible to use CrossFire. If so, then how do the cards work together in OS X? Thanks.