"In a recent interview, Mr. Miyamoto confirmed that a new game will be shown at the E3 Expo in June. He believes that anyone who has played Pikmin games in the past will enjoy playing."
"In a recent interview, Mr. Miyamoto confirmed that a new game for the Wii U system will be shown at this year's E3 Expo. This is based on the Mario experience that was demonstrated at last year's E3 Expo. We'll have more to announce about our plans for the E3 Expo at a later date."
These were both games that were basically confirmed last year to be at this year's E3. However it was never fully said whether or not New Super Mario Bros. Mii was an official game or not, but it seems that it is. I can tell you that if NSMB Mii is some kind of a pack in game with the Wii U, it will sell the system guaranteed and like gang-busters.