I currently use NewsGator to subscribe to Channel9 feeds as well as NNTP newsgroups. The problem with the newsgroup integration is that newsgroups are just too damn busy with threads that I don't care about until I have to diagnose a problem (at which point I can use Google Groups to find what I am looking for). When I post to a newsgroup, I usually want to watch that thread. Also I like to watch newsgroups for information about upcoming Microsoft beta announcements. It is hardly worth it though, since it takes way too much time to sift through the information.
Anyhow, on to my point.
You should be doing more with the Channel9 setup. The RSS integration you have provided into the conversations is fantastic. It is so great that I'd love to see Microsoft's NNTP Newsgroups replaced entirely with this sites integration of RSS into forums as a model. You should create an ASP .NET starter kit for other newsgroup creators to do the same as well.
Loving this site.