Jeff Beehler, who manages all releases of the Team System just started a blog.  In terms of people "in the know" of how we use, built, and decide when to release CTPs, Beta drops, and RTM bits, Jeff is the guy to listen to and ask questions of.  He used to teach 5th grade in between stints at MS so he's got a lot of experience in managing chaos and working w/ unrully people... :)

Check out his blog here.