One of the biggest factors in involving people in SO was the blog and podcast. It provided some idea of what the site should be, pointed out interesting posts, and generally kept me interested. It's great for when you want to know what's going on, but don't have time to filter through things on meta. It would make sense therefore for the various SE-2.0 sites to include a blog site for the duly elected moderators to post on. The point of this site would not be necessarily to post information about technical changes, or duplicate the main blog, but instead to serve as a guiding light for the community, posting information that's on topic to the site. It's one more way for them to succeed.
Note: This isn't totally fleshed out. I welcome your suggestions.