1. I just purchased a beastily equipped PC with a Dual Core processor, scads of RAM and storage with top name components for a mere $800. A Mac is just too damned expensive.
2. I like WinXP Pro. Stable, responsive for my needs and runs everything I want it to run.
If you are going to do it that way, why not build a Hackentosh so you can run OSX as well as Windoze?