Japanese game stores and magazines have given a release date to Mario Kart Wii, but Nintendo haven't actually said anything...

April 10th. That's when they say Mario Kart Wii will hit shelves in Japan. As for the UK? April 25th.

Mario Kart Wii has been set as a Q2 Release, which means April-June, so it's not impossible that the game will release at these dates.

And it's not just the Japanese which say they know the release date, Play.com have set Pre-orders saying that Mario Kart Wii will be release on the 25th.

I guess all we can do is wait for Nintendo to release the official date, but until then these rumours give hope that the game won't be severly delayed like... Every other Nintendo game (I'm looking at you Smash Bros. Brawl/Twilight Princess)

Source.