Long story short: I bought a Mac Pro in August of 06. It was my dream machine. A quad-core, dual-boot monster. I bought it knowing I could upgrade the components (because it was, you know, x86 based). Fast forward to today. Apple sells the new Nvidia 8800GT upgrade kit for the new 08 mac pros, but they're not available for the pre 08 machines. Bullshit, I say. PCIe 2.0 is backwards compatible, so no problem there. There's talk of it being EFI64, but even that can be addressed by a simple firmware update. Currently I'm running the POS ATI1900XT that overheats, and artifacts under the slightest amount of stress. If Apple can't be bothered to support their customers (been a mac user since '89), then I can't be bothered to support them. I may get a PC 8800GT and try to flash the ROM, but it certainly won't be putting money in Apple's pocket. What say the rest of you?