Mode 7, represent!
This screenshot from the Wii U version of Super Smash Bros. was taken by director Masahiro Sakurai and uploaded to the game's official site today. Does it look familiar? That's the island from Lesson 3 of Pilotwings for the Super Nintendo -- in other words, one of those classic locations permanently burned into your memory if you're a fan.
Apparently, it's a stage in Smash. I mean, what else could it be? My guess is that the actual fighting itself will take place at a higher altitude. Either way, cool game for Nintendo to highlight.