I really don't think they could do anything but improve the Skype interface. I'm an existing skype user and I think the interface is about the worst I've used.
whilst I agree the current UI skype on mac is very bad, just look at microsoft mac messenger. A sign of things to come + adverts galore. And if microsoft start using their metro theme which is highly likely, it's just not going to look right on mac os x. Plus have you used microsoft products on mac? mine hasn't been the best experience almost as if microsoft made the program as an after thought or didn't put any thought in it.