UPDATE: Nintendo has responded in a statement:
In a recent interview, Mr. Miyamoto confirmed that a new Super Mario Bros. 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.
Eurogamer pounced on a statement made by Shigeru Miyamoto to a Spanish newspaper in regards to a Super Mario Bros. game for the Wii U and went straight to the company for a confirmation. Nintendo obliged and proudly confirmed that, yes, there will be a new Super Mario Bros. game for the Wii U, AND they will announce it at E3 this year.
Did anyone doubt this would happen? Really? If I hadn't seen Twitter go nuts over this "announcement", I would have completely glossed over it. Nintendo announcing that they will have a new Super Mario Bros. title for their new console at E3 is as much as a given as Microsoft announcing they will have new Kinect games to show off at E3.
Oh wait, hold on a sec… I need to wrap up this article so I can write up an announcement that EA will be showing off some of their upcoming EA Sports titles.