In an update we’ll get into more soon (Suvudu has delayed the opening of the “Cage Match” event), GRRM does drop a piece of information that appears to be about A Dance with Dragons: “There are fifteen others matches you can weigh in on too. Single elimination. If I was a betting man, I’d put my sheckles on Cthulhu myself, but maybe that’s just because I’ve been writing all those ironborn scenes.”