UPDATE: Nintendo have confirmed via Facebook, that the Wii U version is still in development and will release later this year.
Original Story: Just announced via Nintendo of America’s twitter account, Mario & Sonic at the Rio 2016 Olympic Games is due to be released on March 18th in North America.
Oddly, this is for the 3DS version of the game, no details were given regarding the Wii U version, as of yet no information regarding the EU release date has been given either.
Source: NOA Twitter.