Did anyone notice that it has an IPS display?
http://www.apple.com/imac/features.html#displays
iMac 24's have had IPS displays since their inception in 2006. Every 21.5 and 27 inch iMac has had IPS displays, as evidenced by SwitchResX readouts, and the fact that they have around 178 degrees horizontal and vertical viewing angles.
If allows me to run Starcraft 2 at the insanely high native resolution with all the details set to high at 60 fps, I'd spring for it. (the 2GB upgrade)
You get basically no performance benefit whatsoever going from 1 GB to 2 GB even at 2560x1440, see Anandtechs test of just this:
http://www.tomshardware.com/reviews/graphics-ram-4870,2428.html
More info on GPU memory in OS X:
http://www.anandtech.com/show/2804