The LittleBigPlanet series has gotten quite a bit of downloadable content, if you count the various costume packs. With two new LBP games on the way, the powers that be have figured out a way to make sure any DLC you've paid for will continue working.
Any costumes you've bought for the first two LittleBigPlanet games can be imported for free into LittleBigPlanet Vita or LittleBigPlanet Karting. Plus, from now on your costume purchases will all be counted across LBP2, Vita, and Karting.
Now for snippets of bad news. They won't all be available at launch, as the team will still be working on the functionality for some of them. Plus, if you're particularly attached to the Assassin's Creed or April Fools Fragrance costumes, you should know that you can't take them into LBP Karting. Weird and arbitrary, maybe, but I think we can all agree Ezio would have an advantage in a race.
If you want to check out some of the costumes already on sale, you can view the full line-up. Sony also released a new trailer for the Vita title and Karting (below), and if that's still just not enough LBP for you, check out our recent Vita preview.