For gaming you have to wonder when the screen will become TOO BIG, ie you'll have to pan your eyes/head/neck around to see something in the corner if you're focused on the center.
I absolutely love my 24" Dell. Since all the 30" displays have a much higher response time, they didn't interest me at all. I'm a CSS addict and I knew that, for me, 24" was probably optimal for CSS, playing with my friend's 30" Apple Cinema Display I need to move my head a bit from side to side to see the corners.
For me, 1080p @ 24" @ 6ms = the win.
I want to try a 27"... but not for $1500. And I think, for gaming at least, 30" is overkill.
Ideally I want a 2nd 24" panel for dual-monitor productivity work.
-Alex