Since I first started speculating about Hawaii being a possibility for the next region, I was thinking about something^^. How about a longboard as an option similiar to the skates? In my oppionion it would be pretty awesome to use it, especially on coastal roads:3.
Game Freak actually had an idea to use a skateboard in 2nd Gen if I recall, before they ended up settling on the traditional bicycle. It would be interesting if they tried to bring it up again with S/M.