To delete or not to delete, that's a tough question
I had a discussion with a "customer" (or I guess technically it's a freeloader ;)) about why the old version of POP Forums didn't allow you to delete a forum. That's a good question.
The truth is that in terms of the database, there is a mountain of data that is eventually connected to a forum record. It has topics, which in turn has posts, favorite topics, e-mail notification, search word records, moderator associations, moderation log entries... I'm sure I'm forgetting something. That's a whole lot of relational data. Even with the database set up to cascade deletes, that's a whole lot of data. I could do it in a new thread so it didn't time out or hang up the page, but I'd hate to see what happens to a live forum in terms of performance. The biggest pool of data I have involves about 400,000 posts in a single forum, so I don't even have that big of a data pool to test against.
Despite all of that, you can simply turn a forum off, which for end user means it's essentially not there, but I can see how someone on a shared SQL Server account might have limits and they need to blow away a particular forum.
It might still happen... but not by the first beta.