BuddyPress is a suite of WordPress MU plugins that will completely transform a vanilla installation of WordPress MU into a fully functional social network platform. It includes extended profiles, messaging, friends, groups, chatterboard (AKA Wall), and albums. In the recent weeks Andy Peatling handed out the project to the community as he didn’t have time to work on it. Surprisingly, Andy has join Automattic, the people behind WordPress and Gravatar among other projects, to develop BuddyPress full time.
So WPMU users will be able to not only create weblog hosting, but in a recent future, social networks.