i had the vista beta on my laptop (p4m-2.0, 1gb ram) some ages ago and when it booted, it used ~900mb just to boot to the desktop. opening IE (or any program for that matter) would push it into swap.
i refuse to buy RAM so the OS can pig it all. i know you can go in and strip down all the services, but i shouldn't effing have to do that. since W2K is EOL, i'll probably be one of the last users of XP... after that, i don't even know what i'll do, because there is no way i'm buying a computer with 4gb of memory just so windows can use it all, instead of all the other bloaty apps people create these days...