No, Disney does not allow transfers of race bibs.
From the race website
CANCELLATION & TRANSFER POLICY
Registration fees are non-refundable. No exceptions will be made.
If you are currently registered for the 2011 Walt Disney World Half Marathon, Walt Disney World Marathon or Goofy's Race and a Half Challenge, you may transfer your registration to one of the other two races, subject to availability, on or before July 15, 2010. Transfer requests received after July 15, 2010 will be assessed a $25 processing fee. Transfers are not allowed for the Family Fun Run 5K, Mickey Mile or Mickey's Marathon Kids' Fest events. A 2011 Walt Disney World Marathon Weekend race entry cannot be transferred to a 2012 Walt Disney World Marathon Weekend race or any other Disney's Endurance Series event. Race entries cannot be transferred to another person.
They are loosening up on the transfers between races again but not between runners.
I think a better policy is one of a race I am running this weekend
What about refunds and/or credits?
In the event you know ahead of time you cannot participate in the event but you are signed up, you may contact us and switch your entry to someone else. IN THE EVENT OF BAD WEATHER AND/OR CIRCUMSTANCES BEYOND OUR CONTROL WE CAN NOT ISSUE REFUNDS, CREDITS, OR TRANSFERS. Most of the race has been paid for ahead of time with the money we collect from entry fees. As much as we would like to offer refunds we just cant since all/most of the money from entries is gone to pay for the event. Its the nature of the sport and you take a certain risk, as do we, when you sign up. Typically cancelation of ANY event is not something to worry about and is quite rare.
And to further make it simple
Can I transfer my entry to someone else?
Yes but ONLY before race morning and ONLY if you contact the Race Director at xxx-xxx-xxxx
What if someone is caught wearing another persons number?
If youre caught racing in someone elses number you will be blacklisted and not be able to race our races and possibly others for a lengthy period of time. DONT RISK IT! Contact us before race morning and well transfer your number for you.