After a romantic reunion with Mary and some conversations that have been more than a decade coming, the family sat down to have dinner together before John would have to return to his own time, his memory wiped of the happy encounter.
Instead, Dean went with what his heart has desired since he was four years old: the Winchester family together again.
This meant that John Winchester, circa 2003, was yanked to the future, where he was shocked to see a grown-up Sammy and Dean looking seriously freaked out.