I spent last week at MIX07 (my photos).
The thing that impressed me most is the number of times I heard the word "open" at a Microsoft event. WTF? Is Microsoft embrassing open-* ? And if so, what? Open standards? Open Source?
I have the impression that as their "platform" evolves from the OS to Web Services (providing SLAs for Windows Live is a nice move), they realize that 1) they can be more open and 2) they have a lot to win by being more open.
So openness is in the Microsoft agenda. The real question is how high? I mean compared to other attributes, qualities, priorities, like "profitability", "usabilitty", "backwards compatibility", etc, how high is "openness"? This is the real question.