Hey, Chris,
As YAG mentioned, you might want to check out CodeCamp events. The smaller ones tend to get about 75-100 attendees, and the larger ones in the major cities tend to get in excess of 200. The first Philly CodeCamp in 2005 had close to 400, and some of the Boston CodeCamps have had several hundred. Some CodeCamps are better than others, but overall they definitely demonstrate that the .NET "community" is very very strong. The Microsoft Developer Evangelists in the northeast have definitely done a great deal of work to help promote and support CodeCamp events.
I hit the ones in the mid-atlantic, so I don't know as much about the ones in your area. I know that the NC CodeCamps have been successful.
Kevin