I'll be running a Mac by then.
The cost of purchasing (or building) a high end PC to enable good performance with Vista is already closing in on, or has surpassed, the cost of a Mac.
The only issue now (in my mind) is purchasing the software for the Mac platform, which I can accomplish by 2009.
I like PC's quite a bit, but the overall cost of living on the 'bleeding edge' has dampened the enthusiasm I once had. A machine that runs some office programs, some publication and graphics editing programs, and has multi-media capabilities is all I need. I like the performance in the Mac for these basic needs better than the performance in the Vista PC (and I have a desktop that has a Vista Experience Rating of '5.3').
....Corky steps down from soap-box......