User blog comment:BertH/New Forums now available in Labs/@comment-4018164-20121203202440/@comment-452-20121203222333

In your Email Preferences, there is the option: "Email me when page I'm following is changed", but that will disable all following emails, there doesn't appear to be a way to do it only for threads.

You've highlighted an interesting point that should probably be addressed: better email preferences.

There is a new section for Message Walls, so hopefully there will be a new section for forum threads as well.