A Sega press release has suggested that Wii U will be available by November.
UPDATE: A Sega spokesperson has contacted CVG to clarify that the below Wii U date is incorrect and that only Xbox 360, PS3, Vita and 3DS versions currently have a release date.
Original story continues...
The press release in qestion announces that the title character of upcoming Disney animated comedy Wreck-It Ralph will appear in Sonic & All-Stars Racing Transformed. It goes on to state that the game will launch on Xbox 360, PS3, Vita, 3DS, PC and Wii U "this November".
Nintendo has said it plans to launch Wii U in all major markets this year, but has yet to announce a more defined release window.
Scribblenauts developer 5th Cell recently waded in on the Wii U performance debate to declare that Nintendo's new console is "definitely more powerful than Xbox 360 and PS3".