I don't know if this has been said yet, I'm sorry if it has because I undertand the frustration of multiple posts on the same thing, but I think it would be awesome for Sackboy to be like Kirby. He can "wear the costume" of one of his opponents, and be able to use one of their abilities. I mean, they already have LBP costumes for some, if not most, of the roster already. Plus costume changing is a big part of LittleBigPlanet. Some of you might think it's stupid, or think it's too "ripp-off-ish" of Smash Bros, but I think it would be a fun idea.
.. Or atleast to the idea you are.
No, I just haven't seen anybody post anything about it. Usually, I don't click on posts that say "idea for _____ moveset."