There was great feasting for many days, in which all of the characters celebrated their victory, but it soon had to end. After many, many Snoopy Dances and award ceremonies where Vampire Slayer Badges were given out, they called upon the Doctor, Marty McFly, and Doc to take all of the characters back to their respective worlds. There were many tears, and I think Captain America even apologized to M.A.S.H.'s Hawkeye for knocking him out cold, but it had to come to an end. The trio of time travelers made sure that the time space continuum wasn't destroyed from this massive conglomeration of characters, and sent them all back to their worlds.
But it wasn't finished.
They still had many tasks to undertake, including destroying the world's population of zombies and zombie apocalypse preppers.
It seems as though their work will never fully be over until the Lord returns.