Seen listed: -
Michael Jackson The Experience Collectors edition PAL version
Includes Special T-shirt and a very nice special edition case.
http://www.game.co.uk/Accessories/Wi...heal%20jackson
NTSC versions will have a pre-order launch glove, it too will come with a different case but will not look like a collector's edition like the PAL version.
http://www.gaming-age.com/news/2010/11/1-2
Both are exclusive to the Wii.