Really excited for this. I always assumed their "Create with Clay, Playstation Move Demo Thingy" was a tool to create objects for a new Little Big Planet. Then LBP3 came out, and that wasn't the case.
I could still see those tools being used for a game where you create your own 3D models, but maybe a completely new IP. One that takes place in a complete 3D space, unlike the mostly 2D space in the Little Big Planet games (I know you can still make pseudo 3D games, but most levels are primarily 2D).
I still think it will be some type of game, even though "game" is in quotes. Maybe they will release some creation tools as some type of beta, for a game that will come at a later date, to let people get used to the creation tools. That is why they used "game" in quotes, I am just thinking out loud really.
However, MM have always made games that I love, so I am very excited for what they reveal when the time is right.