Oh, but we have seen it already, if I had liked it I would have probably liked Android, iOS or Metro, or what KDE have been working on. I didn't like any of those, I've only ever liked Gnome2 since KDE3 died. It used to be I liked Apple's OS X UI as well as KDE3 and Gnome2. None of the "modern" UIs appeal to me in any way. I don't even use a composited desktop as it adds no real usefulness over multiple desktops for me.
So currently I have only 1 DE with a small dev team that may or may not be able to keep the project in a state that is usable in the years to come. otherwise I have nothing I like.
I've used everything but WebOS, and most of what I see out there is crap.