Kudos to Six Apart for addressing the concerns of the community with an excellent FAQ. If only other companies would respond so well to feedback.
From the TypeKey FAQ:
With Movable Type comment registration, we've provided a great deal of options for weblog owners. At release (remember, we're still in Alpha), we plan to provide a detailed user's guide to comment registration and comment management options. But, for now, we want to provide a glimpse of the commenting options. With Movable Type 3.0 you have options. You can:
Currently in Movable Type, 6 and 7 are the only two options. 1 through 5 have been added to create a varying degree of accountability. While comment registration is not the right answer for every weblog, Movable Type 3.0 and TypeKey provide a flexible system that we feel will work for the majority of Movable Type users."
- Only accept TypeKey-authenticated comments where the commenter sends an email address
- Only accept TypeKey-authenticated comments
- Accept TypeKey-authenticated and moderated comments
- Accept TypeKey-authenticated and regular comments
- Accept moderated comments
- Accept unmoderated comments
- Accept anonymous comments