3. You are locked in to one hardware vendor. (This has not really been any more true for Apple motherboards than for Intel or AMD motherboards in a long time. ATI and nVidia need to flash their video cards slightly differently for Macs, but otherwise the Mac is made up almost entirely of industry-standard, interchangable hardware.)

Interesting point, but I am more concerned with hardware other than videocards as well. However, I was under the impression (I have never owned a mac) that it was difficult to obtain major parts (motherboard, bios replacement) of any quality for a PowerPC system without going through Apple.

Please, correct me if I am wrong; I would have built an Apple-like computer in a second if all the commodity hardware was available.

The true reason many x86-using mac fans have not made the switch is that they can't upgrade their entire machine without getting bent over by Apple.

Why would anyone buy through Apple if their hardware components were made available to the public at a competitive price? If my motherboard fries, I would find comfort in the fact that I can purchase a replacement or upgrade board in a competitive market.