The 5k registration fee includes One (1) Twilight Theme Park Ticket to either DL or DCA that are only valid between Friday, January 27 and Monday, January 30, 2012 anytime after 4:00 p.m to one park.
I am guessing most people will use this on Friday night...a 5k isn't that long such that you need to be well rested (IMHO). And it doesn't make that much sense that a participant would come back the following night? Unless they are a local- SoCal APs are blocked out on Saturday, so maybe those APers would use their AP on Friday (not blocked), then come back Sat night and use the ticket?