Office 14 Ribbon Changes

I continue to be mystified by the design choices at Microsoft.
Just when you think they have finally got on track with a UI (user interface) they backtrack and break it.

With Windows 7 not using the "orb" and now Office 14 (why not 13, are MS really superstitious?) I feel sorry for all the brave designers that revolutionised the way Office looked with 2007
What are your reasons MS?