Hi Nathaniel,
I just completed my first half marathon at Walt Disney World this weekend. It was a thrilling experience that I'm eager to try again. Well, after my legs recover a bit. :-)
As noted at the end of this
Disney Parks Blog summary of the 2012 marathon, registration for 2013 events open in the spring. The exact date of registration opening has not been released. I can tell you that I personally registered last year on March 18, which was during the first week registration was available. I'd check back at rundisney.com in early March for more details.
As for dates, the 20th anniversary of the Walt Disney World Marathon will be held on January 13, 2013. If you're looking for a warm-up event, there are several Walt World Disney half marathons and other distance races between now and then. These include the Disney Princess Half in late February, the Twilight Zone Tower of Terror 10-miler in late September, and the Wine and Dine Half in mid-November. You can also participate in the Tinker Bell Half later this month or the Disneyland Half in early September, both at Disneyland in California. More details for all events can be found at rundisney.com.
Happy training!