I have run the numbers and I can upgrade my 2006 MacPro for about USD1500. This includes 2 5365 quad processors to upgrade my 2.66 quad processor right now and 8 more gigs of DDR2. From what I understand, this upgraded version would be the equal to the 2.66 Nehalem octos for most things. I also should be able to trade in the 2006 MacPro for about USD1,000. Which would let me buy the new Mac Pro for about USD 3700 at the configuration I want. Is the Nehalem processor that much better that its worth buying a new system at more than double the price of the clovertown upgrade? Other than the processor, is there anything else about the 2009 Mac Pro that makes it superior to the 2006 version. For instance, eSata ports? Any advice would be great.