@Geoff...

Well, I am running Vista on a VirtualBox m/c (the host is Solaris SXCE, presently snv-97, VirtualBox v2.0). The guest has only about 630 MB and works very well, sound, USB2, shared folders and the rest... including seamless mode (kinda funny to have Gnome with Compiz and Vista stuff on the same desktop...).

On the other hand, on my laptop I have Vista running VirtualBox 2.0 and a virtual machine running OpenSolaris... BTW that laptop (an HP nx6310) runs much better under Vista (in comparison with XP). It also runs native OpenSolaris in a separate partition.

Hyper-V certainly will get my attention with the standalone product ( I have already deployed ESX3i R2, but the timebomb disaster left some bitter taste ).

There you are.