jamyskis: Real development didn't really start in earnest until around 2004, and it was held up for the best part of a year when accusations were made that the codebase included code from the XP source code lea
That, and creating a full-blown OS with full Windows driver support on the basis of clean-room reverse engineering takes a lot of time. The alpha version I've seen running takes a lot of effort to get running and compatibility is sporadic, but I've seen OpenOffice, zDoom and World of Goo running on it just fine.
It'll work eventually, but I wouldn't bet on a relatively stable beta for the next 3 years or so.
Hell, look at WINE and see how long they took to get to 1.0; and even then I'd argue that it wasn't until very recently with the 1.4 release that things really picked up with respect to compatibility and performance. A lot of games like Shogo: MAD, Blood 2, Fallout 2, and Fallout 1 were nigh unplayable before 1.4.