Im trying to be a little more active on this forum now so here it goes. I have never been in any PGD challenge before but a few things I would find interesting:
There was a discussion on here some time about an AI challenge were everybody would basically code their own AI for a game and compete against each other. It kinda died because nobody wanted or could code the game but I would still find it interesting.

The idea with the "picks" seems good to me. I find it interesting when several people code a game to the same theme and see what the different developers make of it.

Of course we should have a lot of participants. Come on guys!

Cheers!