We're working on a Comment manager for the 3.2 release. Unfortunately, I don't have any better suggestions until that release is out on how to monitor and keep track of comments. We realize this is an issue, and over the next few releases will be doing what we can to easily locate and be notified of new comments on your site.
We wish Facebook had a good administration area for comments, but they don't, so we'll be rolling something out on our own.