Right. The reskin referred to wasn't released in Japan until the early 1990s, when it was released as "Super Mario USA". "Super Mario Bros. 2" refers to the 1986 Famicom Disk System release that is really not so much a sequel as it is a harder version of the original game.
With this in mind, Nintendo of America may have to retitle this one in order to avoid confusion. After all, the game doesn't appear to involve throwing vegetables, plus I imagine we'll only be able to play as Mario and Luigi. While this is technically the 3rd NSMB game, calling it NSMB 3 might not be appropriate despite the return of Raccoon Mario and the return of the "power meter".
Cartoons aren't "just for kids"...but they're not just for adults either. They're for everyone.