It would seem that Ubuntu is in a race with Microsoft and Apple to make a massive change to the way we use desktop.  With the HUD and Unity they are trying to moving things in a new way and change the way we all work.  While I am still on the fence on Unity the HUD is something I hope Apple and Microsoft embrace and extend.  This is a nice article from the man himself, Mark Shuttleworth, about his plans for the future of User Interfaces.