Why do desktop LCD monitors have much lower max resolutions then laptop LCD's?

I have a very ordinary 3 year old laptop with a 15.4" display that has a max resolution of 1920 x 1200 pixels (WUXGA). It's a great display. I love having all that screen real estate that allows me to see multiple applications at once. Sometimes I increase the font size in my browser if I'm surfing at arms reach but that's it.

A 15" desktop LCD has a max resolution of 1024 x 768 (SXGA). The 19" LCD monitor I have at work doesn't do much better with a max resolution of 1280 x 1024. To get the same resolution desktop LCD I have to go all the way up to 24".

Why isn't anyone selling a laptop quality LCD packaged for desktop use?