The announcement coincides with the release of Donkey Kong Country: Tropical Freeze on the Wii U, and producer Masahiro Sakurai adds that Diddy Kong's flexibility has been increased for the new Smash Bros. title.
Diddy Kong, the 24th character confirmed to appear in Nintendo's all-star roster of mascots and characters, made his first appearance in the series on Super Smash Bros. Brawl on the Wii. He's also one of the more capable platforming sidekicks: he has previously headlined his own N64 kart racer in 1997, and even rescued Donkey Kong from Kaptain K. Rool in 1995. Beat that, Tails.
Nintendo is yet to announce the release date for Super Smash Bros. for Wii U and 3DS.