See I'm still waiting for the BA Specially oriented Water/Fighting Polar Bear. There really aren't any more dual types that haven't been done yet... although I could totally see this guy being Water/Dark.
Polar bear would probably be part Ice no matter what. :P I CAN'T see Mijumaru being Water/Dark, but I'd bet money not a single soul bet Piplup would become Water/Steel (and I bet there were awful few people who DIDN'T bet Water/Ice).