Media Molecule is no stranger to partnering with companies to get content into LittleBigPlanet. Just recently the studio released a costume for Octodad, a character from the indie game of the same name. There's even costumes for games like Don't Starve and Oddworld as well.
Do you think Yooka-Laylee costumes in LittleBigPlanet would be a good idea? Even though Playstation fans may have not had a Rare game on their console, they are getting the next best thing, Yooka-Laylee. I'm sure Playstation fans are just as interested in Yooka-Laylee as everyone else is. These costumes tend to sell well so I feel it'd be a smart decision on Playtonic's part. I also remember reading one employee who used to work for Rare had left and joined Media Molecule. I can't for the life of me remember their name. Either way, if it doesn't happen there's plenty enough tools in the game to make the characters anyway. A friend of mine made a pretty decent Banjo.