Nintendo has just formally announced New Super Mario Bros. U for the Wii U. It looks to expand upon the Wii's New Super Mario Bros. with new forms of gameplay, such as boosting where you can place blocks on the run, and a flying squirrel suit for moving around obstacles.
Little was shown during the short demonstration, but four-player co-op—which I'm sure many of you consider competitive—is confirmed. A release date is unconfirmed but a release date on or around launch is suggested.