MindMeister is now out of private beta and it looks like they’ve added some interesting new features to it. The complete list can be found here, but at a quick glance I’m really impressed with the new UI. Much cleaner and more intuitive. In particular, I like the way they revamped the Publish page to make it easy, but still in your face obvious that you’re making your work public.
You’ve always been able to receive Skype in fellow collaborators, and find related info in WikiPedia and del.icio.us, but new to the mix is the ability to receive updates via Twitter! Anytime anyone edits or updates the map, you’ll receive a private message in Twitter alerting you to it. What a great use of Twitter’s new open API.