Is this out of the question?

Add a field to the review section for movie/DVD reviews. But when someone is entering these reviews they could have the option to post a copy of it to the forums as well.

This way, a reviewer can decide for themselves if they want to begin a thread or not. In either case, the original review in the review section would be closed for discussion.

Anyone wanting to start a new thread here about a review they read in the review section could do so.