This is the most detailed article on this subject that I've read to date. This situation is more and more alarming. We find that beyond the calling home every day, this software is beta. It is beta software that can't be uninstalled.
IMHO this is spyware. What it does goes beyond what most people believe that Microsoft needs to do in order to check that it is a genuine copy. The fact that the information sent and the scope of the phone home behavior was not fully and cleary disclosed to the end user makes Microsoft untrustworthy.
Personally, I don't think both shoes have dropped yet. I may be wrong, but I'm guessing that there is more to come.