If you buy the right processors, it'll work fine. I believe we need the 771 socket XEON processors. Going to quad cores would require the 53X5 series processors. At the moment this is probably not financially viable but in a couple of years, who knows? I reckon that my Mac Pro is the last computer I'll be needing for a long time and I certainly anticipate upgrading the processors, RAM, hard drives and graphics card(s) as and when the prices of these upgrades slide towards affordability.