I'm strongly considering signing up for the half as well. I'd love to do the full (or the Goofy) but there is no way I can train for a January marathon, since I have a medical condition that means that I cannot run outside when it gets cold (and I live in Ontario), so December (and most of November) are out for long runs (I know I can run indoors, but, honestly, there is no why I can run in a circle or on a treadmill for that long).
Does anyone know when the half filled up last year? In other words, about how much time to I have to decide?