This looks like an interesting, important summit for the Social Web. BuddyPress is mentioned as one of the projects invited to attend. It says that only project committers are invited to this summit. I hope Andy (who lives in Vancouver, BC) is going or has asked JJJ to attend — or at the very least has asked someone else to represent BuddyPress. The one-day summit is in Portland, OR on July 18.
I, too, was a little taken aback by the exclusivity. However, StatusNet Inc. clearly stated that they wanted to have a small group of people that are actively involved in managing and leading the various projects. This does make sense as it is often too difficult to make substantive progress on sweeping issues when there is a large group of people all pitching in their two cents. I believe it was mentioned that future summits would be open to more participants — but that does not mean it will be an open summit.
As far as the Internet Identity Workshop goes, I believe whereas there are similarities, there are some big differences as this summit targets Open Source projects. It does not include corporations with proprietary platforms.