geekiegeek: Just brought the real deal in the form of a 27" Dell Ultrasharp (same LG panel as the iMac). 1260x1440 wow! This thing is fantastic. If you go for anything above 24" I would definitely recommend the higher resolution - I brought a 1080p 27" 4 weeks ago and sold it to buy this one.
Personally, I'm waiting until monitors with higher pixel density are available.
Pixel density doesn't seem to have changed much over the last few years.
A 24" retina monitor would be just right for me.