The Super Mario Bros. series has always been a little irregular in the number of worlds it offers. Super Mario Bros. began a tradition of eight, while The Lost Levels added five more to that, including the elusive World 9, which could only be accessed by not warping (and it really stunk in All-Stars if you'd open it, warp later, then save).

Super Mario 2 offered only seven worlds, while Super Mario 3 went back to eight, with the ninth world being the "Warp Zone." And then Super Mario World brought seven lands, the Star Road, and the Special World.

Things went back to basics in New Super Mario Bros. for the Nintendo DS with eight worlds to explore, and it appeared that New Super Mario Bros. Wii was going the same way... at least, until the above image appeared during the latest edition of Nintendo Week.

Unfortunately, we don't know anything more, except that this might relate to the "fantastic secrets/features/surprises" ONM spoke of in their recent Q&A.

Below, you can see the Nintendo Week episode for yourself, featuring Shigeru Miyamoto and some new Excitebike World Rally footage.

As for the screen above, look for it around the 4:23 mark.