Nintendo has just unveiled Super Mario Bros. U, a re-branding of last year's Super Mario Bros. Mii. A short video was shown off, which looked like it included a mix of old and new items, including the raccoon tail, Yoshi, and... something that looked like a blue Yoshi that burped bubbles. Or something.
Like New Super Mario Bros., the game will feature four-player co-op, but it will actually use the Wii U tablet to take things a step further. A fifth gamer will be able to help (or hurt, if they're a jerk) using the screen, making it the first Mario game we can think of with five-player co-op. It will also feature Miiverse features that let you put notes on different levels on the world map, helping (or, again, hurting) others online.
We'll post a video soon, but stay tuned for more details from the show as it arrives.