I've seen and tinkered with the Longhorn beta. It did have a GUI and was, aside from being incredibly buggy, a complete operating system as near as I could tell. I also have no curiosities about why MS is waiting until 2k5. Longhorn abused my system resources in an incredible way. It used nearly 200 megs of RAM and after a basic install was running about %30 of my CPU. I suspect that will be changed, but I also suspect that they know that the average user will be unable to run the operating system at this time and have chosen to wait on the release.

Just my thoughts.

-Zen