This rumor is from: http://gonintendo.com/viewstory.php?id=140295#comment-section
They also say the next Mario/Sonic game may not be a sports game.
Here´s the text:
It's been awhile since we heard from Wentos the Travelling Salesman, the mysterious man that seems to get Sonic information spot-on. This same person offered up information about Sonic Unleashed that ended up being completely true. When Wentos the Travelling Salesman, Sonic fans sit up and listen. This time around, Wentos had a bit to say about the next Mario and Sonic title, as well as Sonic Colors possibly going to 360/PS3.
On the rumored next Mario and Sonic outing: “Without giving anything away…this time, it’s not a sports game. It’s turning out quite well. I think some of you may be a little surprised.”
On Sonic Colors Wii/DS exclusivity: “…Wii/DS is a much more cost-effective pairing, especially for an ‘experimental’ Sonic game like this where they needed the financial and developmental freedom to craft 50+ (!) stages. The technology and design plan is all set up to do the port on Sonic Team’s end. Of course, they need strong sales to justify releasing it on the other two platforms (with enhancements, more money spent, etc) in the first place, so it’s all up to you guys.”
Wii don't mind. 
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