A rumor originating from Paul Gale Network says that Nintendo is planning a Star Fox/Metroid game for the Wii U.
The Retro Studios-produced game would be set in the Metroid universe, and would allow players to control both Fox McCloud and Samus Aran. The Fox sections would mix space battles and platforming, while Samus' sections would be in first-person.
This crossover is still in the rumor stage, and PGN's predictions have been hit and miss -- they called PlayStation All-Stars, but nothing has come of the supposed Rocksteady Ninja Turtles game they reported -- so take this one with a grain of salt.
[vgn.]