Why Linux GUI's are not yet mass adopted
If you are new to Linux and are presented with something that looks similar to what you're used too, wouldn't you get the automatic response to expect the exact same experience? I think it will never be the same experience, there will always be differences in behavior. It's even worse. By getting something which looks almost identical to what you're used, you set the expectation level that it is the same. Any difference will frustrate the average user. While if you are presented by something fresh and new, you will notice that you are dealing with something different, inherently making you more receptive for a new experience and liking it. Designing the GUI for the mass audience with this in mind, could lead to linux being a real alternative.
Im not saying that there's no fresh or new things in for example Gnome or KDE at all, but if you look at it from the other perspective. You can't find many ground breaking stuff either. To get more specific, one annoyance of my Windows XP experience are the pop-ups that steal keyboard focus. Some App is running in the background while you're typing a letter. Then Boom, halve way a sentence and the second part of the sentence gets lost in a pop-up (e.g. windows explorer's). Wouldn't it be nicer if the GUI detects that you are busy typing in one App and consequently wait for a moment you stop typing and only then show the pop-up? Nobody types full speed 100% of the time, so there will be a lot of suitable moment's to let the pop-up snag your attention while not being so annoying.
This is a minor example, but how about some more revolutionary new idea's? Wouldn't that make Linux more enticing to try and use?