Personally I don't think Sonic repeatedly copying Mario titles is going to get the series very far as a whole. If it makes very different changes from Mario Galaxy and establishes itself as a unique game, it could spark interest in Sonic again, and for that matter the Wii U, as the U has not has any third party support this far. If it just blindly copies Nintendo, it will once again fail to make a modern, relevant series that they have needed for so long.