Pshh, that is not all that is changed, and Maya has needed a UI overhaul for years; I think it is a big step toward bigger changes.
Check out the thread over at polycount:
https://boards.polycount.net/showthread.php?t=70775
I, personally, can't wait.
This is a bigger update to Maya than I have seen in a long while.
P.S. The viewport 2.0 looks amazing.