I think I'll have to refrain from commenting on Vista any further: it's six months since I removed it from my systems and went back to XP. The only way I'll get it again is if it comes as standard on a laptop, and even that's unlikely. Until then, I'm talking through my ... ear ... when it comes to the current state of Vista.
I think it has potential, on future hardware, but I'm basing that on my XP experience - I had very few problems, mostly hardware-related, and none since SP2 came out. My hardware is old and "settled" now, with solid XP driver support. But I could be wrong about that - e.g.
this.
I've spent so much time with UNIX systems now that I think that's the way to go. Linux for me, but I can see how Mac OS X makes sense as a "friendly UNIX". I don't think they should be taking credit for the security benefits they gained by choosing a UNIX architecture, but I expect nothing less from Apple these days.
