Well, I posted a topic about an IGN article that talked about it in more depth but it was buried I think.
Here it is again
http://xbox360.ign.com/articles/872/872701p1.html
From what I understand, there are 7 hub worlds which are the "levels" so it will be a platformer, at least on a certain level. However they say that Banjo lost most of his moves...
How many cups of darkness have I drank over the years? Even I don't know...