I say that anything goes until the Master List goes up (and even beyond that!). If you do make a claim, go ahead and leave a claim note. I probably won't update the post, but it will help me figure out who you drew for when I make the master list.
If and when you post, don't forget to use the fantasy fest tag. That will be a great help. I can't wait to see what you will do!
And thanks for volunteering to make icons! More than one person can work on anyone's requests. The icons will come out different from each person. If you want to check on LJ, there's some requests there. I am going to make an icon request here, but I'll do it in a separate post so as not to obligate you.
I'm so happy to hear you like the Art Big Bang idea! *bounce* *HUGS*