Jorescue,
On-line may be until the end of the year but if you call you can go out further (500 days).
The routes for the Half and Full marathons have been altered since I ran them but they do route you under Spaceship Earth and then out into the parking lot to the finish line so you are briefly in Epcot for the Half. For the Full, you go through all 4 theme parks. We came into the back of Epcot at the International Gateway between France and Great Britian, went through the countries counter-clockwise (toward the American Pavilion), right down the middle toward the Fountain in Future World, under Spaceship Earth and out into the parking lot to the Finish Line.
The new Half Route starts out on the road in front of Epcot, goes all the way down to the Magic Kingdom (up Main Street, through Tomorrowland, through the castle, out through Frontierland) and back to Epcot just skimming Spaceship Earth as I said.
The really wonderful part of the Full was when I was limping my way into the back of Epcot and came through the International Gate, it was before 11am so no one was back there yet in the Countries area (except a few CM getting ready for work) and it was quiet and time to reflect on the accomplishment. Then when you run into FutureWorld there's more people and it's gently downhill around Spaceship Earth you get a little hitch in your giddyup and then go out into the parking lot where the crowd is, people are cheering, the announcer is calling out names of people finishing, it's an emotional finish and a relief to cross the finish line.
So go do it and enjoy the experience.
Bama ED