Mario & Sonic at the Rio 2016 Olympic Games
Announced at the Japanese Nintendo Direct (Sunday, May 31, 2015)! The fifth game in the Mario & Sonic Olympic series; third game of the Summer Olympics. Takes place in Rio, Brazil. Actual Summer Olympics happens in August 2016. Exclusive to Wii U, Nintendo 3DS and Arcdes. 3DS Release: Thursday, February 18, 2016 (Japan), Friday, March 18, 2016 (North America), Friday, April 8, 2016 (Europe), Saturday, April 9, 2016. Wii U Release: 2016 (Worldwide). Arcade Release: Spring 2016 (North America), 2016 (Japan/Europe).
They just revealed this in the Japanese Nintendo Direct yesterday for Wii U and 3DS!
I loved the London 2012, really wasn't expecting them to make another one though.
Nabbit, Diddy Kong, Rouge and Jet will be playable.