I still say they should get rights to the Pogo characters (after all, it is somewhat Disney since Walt Kelly was an animator at Disney) and do Splash Mountain: Election Day Special.
Either that, or have "Deck Us All With Boston Charlie" playing for a holiday version.
Problem is, Pogo no longer has the popularity and awareness that he had throughout the 50s and 60s.
So, on a more realistic note, Monsters Inc. would do. I'd like to see that Sully in a Santa suit.
On a related note, I have seen a bit of a Jungle Cruise Christmas down at WDW... Chief Nami was once wearing the mouse ears Santa hat for a while (on a trip on April 1st).