Windows 7 has a great desktop experience, and it's whats keeping me from switching over to Linux. Gnome 3 is really close to it though, if not for the font rendering[1], games[2], and comfortable software I would switch over to Linux. I think Linux can do it if the people who develop software with a GUI only work with their GUI to develop their software. This would force them to be frustrated enough with their application to make it work, or just give up. Either case, it's better than wasting other peoples time.
[1]: While the freetype2-infinality library tries to solve this problem, it's not quite there yet. It's close though
[2]: Wine is a good effort, but it needs to look more like Windows 7, and less like Windows 2000 (lots of the great UX was introduced in 7 in my opinion).