Actually, dropping out now that the fight is effectively over puts Romney in a better position for VP selection. (More compellingly, Romney has strength in states that are actually in contention; Huck's strength is concentrated in states that would go Republican if they ran a ticket consisting of a department store mannequin and a potted plant.)
That said, I don't think McCain has the temperment to bury the hatchet with one of his former rivals.
I don’t think either would be a good vp. None of the candidates, including Fred, is a home run hitter.