The idea has merit but I'd like to fully flesh it out, turn it around, and look at it from as many angles before we do anything. It's generally better to have fewer forums than more, even if opportunities exist for specialized topics. The more people you can digitally cram into a room (forum), the more active the discussion.
A few questions:
Do we need to look at the moderation policies of The Armory? Would doing so meet the needs here, or is the primary concern a more private forum?
Would it be read-only to non-members, or no access at all? If that's the case, how will we get the word out about it to encourage participation there?