OK, went to CompUSA and they were JUST setting up the 24"... I mean the box was on the floor and they were running whatever setup applications CompUSA uses to get the systems setup with stock crap.
It's too big. I'm being serious. It LOOKS great, but it's too big. It would be cumbersome to use, the 20" is honestly, in my opinion, the ideal size. The 17" is a big rinky-dink, the 20" is a perfect compromise between size and usability, and the 24" is a monster.
That's just my opinion, of course, but even if it was in the budget (and it just about is) I don't think I would buy it. If they put the 24" iMac internals in a 20" case (or better yet a headless box) I would look at it, but I can't see much of a need for the 24" other than status symbol.
If you are doing serious video/layout work and need that screen space, you're better of with a Mac Pro, and if you're not the 20" is much more practical... ah well, seeing the improved quality of the 20" iMac screen since the last time (Rev A G5's) I looked convinced me I want one instead of a new mini+my Dell 19".