I love the idea of doing the games anonymously. Perhaps it's because I don't have a big fan base, but I'm finding that my fics are doing much better in anonymous fests as opposed to the fests where the names are posted. I think it levels the playing field quite a bit and allows stories to be judged on merit, not on reputation (though please don't think that I'm trying to say that reputation isn't based on merit - it is, it simply carries a great deal of additional weight of its own). And I agree with jin_fenghuang's point: readers will know who is participating in the Games already, just not who is writing which story (though I'm sure that many will be able to guess).
Another great idea: having maximum and minimum limits on stories. Perfect. Again, levels the playing field.
I love the writer/artist collaboration idea and I'm entirely comfortable with having them assigned. If it's a true collaboration, there's no reason that the writer and artist can't agree on how to approach the work, so I don't foresee the difficulties of having an artist who absolutely hates what they have to create artwork for. Would there be any reason that a writer would presume that their story is more important than artwork created to complement it? (Of course, in RL, I'm an artist; my only creative writing is HP fanfiction, so I'm quite biased. *g*) It may also help to minimize drop-outs, since in addition to the overall team support, there would be partner support as well. I'd be worried if there wasn't some formal manner of partner assignment, though, since I don't have the relationships that many writers and artists have in the community. I know which two artists I adore and would personally like to approach, but I also imagine that they would be approached by many other writers, too, and that logically, the artist would choose someone s/he knows well as opposed to a little-known writer.
I'm so glad that these discussions are taking place and that the Games are still alive! They're a huge amount of work, and I was worried that after DH and the end of Smutmas, the Games might also have taken their last curtain call. Thank you all so much!