Another reason to run Mac OS X, an operating system with a major point release every year and a half or so.... also an extremely nice interface that doesn't require such an intense graphic card. Windows is resource hungry as it is, i would imagine microsoft would have only tried to alleviate this problem instead of making it more significant. A 7 year old machine still meets the OS X requirements, I can't even guess what kind of percentage of Windows running machines will not be capable to upgrade to Vista (SP4? SP5?).
Macintosh computer with a PowerPC G3, G4 or G5 processor
DVD drive for installation
256MB of RAM
3GB of available hard disk space (4GB if you install the developer tools)
Kind of funny because it doesn't mention Intel processors (I only assume because all Mactel machines already have the newest OS X).