The Wii version of Sonic Unleashed is not being developed by Sonic Team, but instead by Sonic Rush developer Dimps, magazine Nintendo Power's saying.
According to NeoGaf forum posters, the article said that Dimps' version of the game will use an entirely different engine to the Xbox 360 and PS3 versions, include different levels and gameplay elements, and heavily focus on 2D gameplay.
So whilst Wii owners should expect a game somewhat different to what was seen in the trailer earlier this year, there's every chance they'll get a fantastic Sonic game anyway.
In fact, dare we say it, they might get a better version. Compare Sonic Rush Adventure (Dimps) to Sonic the Hedgehog 2006 (Sonic Team) and you begin to wonder.