Copyright, community and common sense
Microsoft has gone a very long way to open up their development process and get stuff out into the open early. Most of the program managers and leads that blog think this is an awesome practice, because they're getting real customer feedback much earlier in the release process than they ever used to before. It's good for Microsoft, and it's good for customers.
But then you get lawyers involved. A part of me always wanted to be a lawyer, because I love to argue, but it has become the profession of ill-repute. Here's a guy being given a hard time for something that is out there on a PowerPoint. As far as I'm concerned, the gloves are off at that point and it's a bona fide news event and the standards of fair-use in reporting should be applied. If that's not the case, then it shouldn't be put out there for public consumption.
I realize there's a time and place. I'm on an NDA list for ASP.NET and tools stuff, so I could get the right information while writing my book. That's a lot different, certainly, and I of course would never reveal anything told to me that wasn't put out there for public consumption. But this guy was treated poorly, and it's a step backward in an era where code monkeys are finally respecting Microsoft and its products.
In the amusement industry, which I cover for CoasterBuzz, there are two kinds of amusement parks you run into. The first kind want total control over everything, and won't allow you to post anything. The second kind will announce a new attraction, send you photos and video, invite you to construction tours, and basically do whatever they can to foster a fan community. While one could argue that these communities are a relatively small portion of your audience, are they really when the rate of information dissemination is so fast? That's a hard question to answer, but when you're Microsoft, pushing around the community is certainly not going to win the hearts and minds of anyone.