Being that this question keeps popping up I'm going to address it here.
It seems the ProBoards, in their infinitely non-existent wisdom, decided they didn't like something in the NSFW section of the old forum we had there. They threatened that if it wasn't removed they would shut down the whole board, yet never actually gave any indication as to what it was they didn't like. In order to ensure we can continue having a space for communing with one another, the NSFW section on that board got removed and, being that discussion of moving the Forum to somewhere with more control and freedom had already been going on, it was decided that it was time to move the forum to a new locale.
It'll be rough for the next few days as members transfer over, threads are built back up, and forum features are tweaked. I ask that people be patient and understanding during the transition. Thank you.