Microsoft will soon begin "Xbox Live and Kinect Beta Program" several readers claim to have received invitation via Microsoft Connect. The invitation itself includes little information about the program, though it notes that participants will be provided with "a unique opportunity to see pre-release software."
It also notes that an "audio change" in said software willn't allow participants to use individual or party chat with anyone that's not part of the preview program. This could indicate that participants will be trying out the new Kinect dashboard seen at E3, which featured a new video chat application.
The email address attached to the invites appears to be valid, Microsoft has yet to respond to inquiries into the validity of the invitation.