In reply to Alec Kinnear.

Comment caching is here inside Thoughtful Comments, along with a new and improved interface, in line with WP Admin improvements. Cute little icons instead of just text links (Jeff has the old interface above).

We welcome any feedback and any improvements. We'd also love to see Thoughtful Comments integrated into core to:

1. improve moderation for busy sites.
2. improve performance on sites with lots of comments.

What we would really like to see is more robust built-in commenting in Wordpress itself. Thoughtful Comments is very simple, clear code with years of field testing. Anyone who knows anyone in core with an interest in comments, please let us know how we could help move the process forward of integrating this functionality into Wordpress core.