Good one, Jason. I concur with almost everything that you say here. I do think that you have to realize that Microsoft has such a history of strongarm tactics that it will take a long time for people to trust its motives.
I'll also say that there are some unanswered questions. For example, at OSCon last year, in the Q&A after Craig Mundie's presentation, there were a number of questions about hidden patents in Microsoft's shared source, and he answered somewhat evasively but left the definite impression that the answer was "yes." Given that a key element of open source is transparency, in the service of user control, hidden patents remain a block to trust.
Still, I agree very much that there is a "move to the middle" by both proprietary software vendors and open source developers. I hope to see it continue, and I most certainly hope that the discussion can get into the right room. It really helps when key Microsoft folks like you come out to engage in the conversation.