XP, Part the Two 
XP-ified Saturn. So far the only major complaint is that while XP runs Diablo, it does so painfully slowly -- even worse than the laptop does, something which makes no sense to me.
Thus far everything else works ok.
Oh except for the logon process, which is XP-Home-esque instead of NT-esque because XP-Pro needs to be jammed into a domain before you get that kind of interface. It will do the 'switch user' trick, which is nice, but I'd kind of prefer the NT behavior.
Impossible to make me happy, eh?
I still need the Norton AV disk so that I have an AV program.
I should get povray going on a replacement wallpaper...
One thing of note: as a result of this process, I don't have Linux installed on Saturn at all. I'm totally Microsoft at the desktop. Can't really say for sure what that means or how long it will last, but we will have to see. I'd
really prefer a faster computer to act as a Linux back-end, though. Sadly this is not to be…