If you are not already reading Jamie's blog then get on over there. Jamie is working on Schizoid, the first XNA game to get an XBLA release, and he's posted some information about what he thinks of XNA and a few rumours about future releases.

As you can see from an his credits Jamie has been around the game industry for a long time and worked on some major titles. So when he starts talking highly of XNA people need to listen.