Super Smash Bros 4  for Wii U and Nintendo 3DS was announced back in 2011. We had to wait two years to be able to see the first screens and videos of  the game, although a release date was never officially given by Nintendo.

According to a listing update from Newegg, an online retailer, the game will be released on May 16 2014.

Super smash bros newegg 600x270 Rumor: Super Smash Bros Wii U & 3DS release date revealed | VGLeaks 2.0

Thanks, Examiner.