The short version: comments are back. They’re powered by Disqus, and you can log in with one of several accounts (e.g., a Facebook, OpenID, Twitter or Yahoo account).
The long version would have involved an extended whinge on the complexity of getting comments working in Movable Type, how hard the server has been hit by the commenting engine of previous versions of Movable Type, an explanation of why I haven’t abandoned Movable Type for WordPress, my adventures in not getting comments, plugins and third-party extensions to work in this new Movable Type Pro install, still another justification for staying with Movable Type, and my adventures with comment spam.
But basically I wanted a pushbutton-simple commenting option that did not hammer my server, and Disqus seems to fit that bill quite nicely. We’ll have to see how it works in practice.