Alright, so we already know about the Bee Suit and becoming a Boo ghost thing. But did you know we now know the other 4 suits?
http://www.nintendo.co.jp/wii/rmgj/action/action.html
Looks like we got:
Bee Mario (Bee Suit)
Ghost Mario (Ghost Suit)
Rainbow Mario (Star)
Ice Mario (Ice Flower)
Fire Mario
Spring Mario
http://www.nintendo.co.jp/wii/rmgj/action/action.html
Looks like we got:
Bee Mario (Bee Suit)
Ghost Mario (Ghost Suit)
Rainbow Mario (Star)
Ice Mario (Ice Flower)
Fire Mario
Spring Mario