It has a lot of potential, but the issue is still the same as with standard Linux: it needs money and some killer consumer features to win the market share. Money in order to convince OEMs it's worth it, and consumer features so that people will actually want to buy it over OS X and Windows.
If Google were to head up the project, then it won't have money issues. But that would mean they would need to get off their ChromeOS hobby horse in order to develop a desktop Android, and I'm not so confident they'll do that.
The one consumer feature I can think of is tight Android phone integration, similar to iOS and OS X. However, that would mean they would have to develop a system that would work with all the (very fragmented) forks of Android developed by mobile OEMs.
All in all, there would need to be an appeal for a large following in order to gain market share. Without it it's in the same boat as Linux and all other minor OS'es.
As for GUI...that's all dependent on the developers. I've seen really pretty Android interfaces and really ugly ones too.