I hope we get a DK Stage first, all the other Newcomers have had a stage to fit them revealed prior, or at the same time as their reveal (as was the case for Sonic), if I recall correctly. Exclude the dudes who were revealed in the initial trailer.
As much as it's probably gonna be from Returns, my dream Donkey Kong level is a beautiful 3D version of the Donkey Kong Arcade construction site, with a beautiful city in the background, girders on hooks that swing in from the side serving as extra platforms, and a sign in the background advertising "Stanley's Extermination" as a cute touch.
Basically like that one level in Street Fighter IV.