Actually, it seems like this screen might well be worth the money for some people. Apparently, aside from the extreme resolution, it uses a top-grade IPS panel. You get nice colours, dark blacks, sweet viewing angles, etc. And Apple has a pretty nice system in place to control the display; it doesn't work at its full resolution for showing you the OS desktop, as that would make text too small for many. Instead, it runs at a standard 1440x900 resolution, but it uses the extra pixels in between to enhance sharpness. If you want more viewing area, however, you can sacrifice some of this sharpness boost for viewing area. You get the best of both worlds.. and then some.
http://www.anandtech.com/show/5998/macbook-pro-retina-display-analysis
If you can pay for it, that is. (And if you have a practical justification for paying for it, like professional work.)
The only real disadvantage of this system is repair-ability. Almost all the parts are fused/glued together. If anything breaks, Apple will probably replace the whole unit and give you a new one... which is nice while it's on warranty. After warranty, if something minor breaks, you're screwed because of how expensive a part replacement would be. This sucks for a laptop that starts at $2k and can be configured for like $4k.
Give me a good quality IPS screen on a Lenovo ThinkPad, then Apple can gtfo.