First at all, you are making a great job with this section
I have some ideas and comments that can be helpful ( I hope :D):
Think you can open two WIP threads for non audio and audio competitions. Something like this:
ASF_non_audio_AGUST09_WIP (or ASF_acting_)
In this threads , like now, are the rules and the participants submit in there the WIP of their animations.
In the last week of the challenge you can open 2 threads more for final animations only:
In this threads only final works, and no comments. The participants can update their animations until dead line. Think that is more esay to review the animation in this way. When deadline arrives, you close the threads, and open the two voting threads.
The winner circle is a cool idea, and you can make a sticky thread with the winners of every month and their animations.
Maybe you can talk with Roberto Ortiz to promote the winners of the monthly competition on the top banner of CG forum (like the “sketch of the week”), think that can be a nice prize for the winners and a good promotion for the Animation sessions
My suggestion is that can be only audio challenges: One month a dialog, and other audio FX(In this form, you push the imagination of the animators to create something around of some sort of sounds or music)
Again, you are making a great job in this section and if I can help you, let me know Cheers!!