The awesomeness factor is off the scale. It has every feature I wanted to see in a phone... Let's hope the price is reasonable too and this could be a real winner.
It does look a lot like some sort of custom skinned Android, but that's not a bad thing. What alternatives do they have? iOS is impossible to use on a non-Apple device and inferior to Android. Windows Mobile lacks even more features than iOS. Symbian is a joke.
Which leaves developing a custom OS, which is nigh impossible, or using Android. Mozilla lacks the budget, developers and partners to develop something that even Apple and Microsoft barely manage to do.
So the best option they have is to use Android, give it a personal, Mozilla-themed skin and throw it on the market. If HTC could do it, I don't see why Mozilla couldn't develop a custom UI. Besides, that phone's features are so awesome I would want it even with Windows Mobile.