This is NOT correct for 2010. More participants so the numbering schemes have changed. I also expect an additional wave in the half based on Disney webcasts. I seem to recal a change to the full start. This is based on the new race times of 5:40 am. I ask why not 5:30?
Anyway, the increase in marathon spots pushed the first half number up to 35,000 making at a minumum the fisrt half corall to start with 35,000.
http://disneyrunning.com/09fullchutes.html