I run a Mac Pro, 2 x 2.66 GHz Xeon, 2 GB RAM, 250+500
GB HD, 23" display, that I use for work and family. The
new public Beta of Boot Camp (V1.2) now supports Vista.
I just installed it and Vista Ultimate on the weekend.
Works very well for me. For work I do have to use both
Windows and OS X as the product (Java-based) we make
runs on both platforms.

That said, I much prefer OS X and I try to work from OS X
as much as possible. For my family I bought a 17" iMac
and have a wireless network. Again I much prefer OS X
for the family. I hated being the tech support gury for my
wife and kids whenever Windows bugged out. I have yet
to establish if Vista is any more reliable than XP for home
use, but XP was a major pain...anti-virus programs
screwing up the works, registries getting screwed up, etc.