Well, Cory, I've had Windows Server 2008 (basically a beefed up Server version of Vista) on a PIII Celeron 600 with 384MB of RAM!

Its...not pleasant, but not as bad as you'd expect either.

Have to say though..its hard to believe that the B&W is 10 years old...I remember seeing photos of them when they were first released, back when I was 14, thinking, "wow, this is the future of the Mac".