As has been discussed before, new forums are created when the demand warrants it. If there is an overabundance of threads about a particular topic, we consider the creation of an additional forum to take the stress off of the forum currently hosting those threads. It is our job to maintain proper balance on these boards, trying to make sure that all forums currently created are being used properly and effectively.
Forums that have been proposed by users have been wonderful suggestions, but the content currently being posted on these boards do not warrant the creation of the suggested forums. We find it difficult to justify the creation of a forum if there is currently no influx of traffic demanding its own forum.
We should also remember that this is AppleInsider and that we try to keep the forums here as on topic as possible. As such, this is why we have shot down ideas of forums about Gaming and Web Design in the past.
Please remember that this is not a challenge to create enough threads to convince us to create a new forum...