I see no problem with "only" 30 characters...Its not like they all have unique movesets like in Smash Bros or anything so I really don't see why people care this much. Also, counting the Koopalings as 1 character, you still have 24 which is the same as in MKWii.
EDIT: I would also like to say that the presentation in this game (the menus and such) is leagues above that of MKWii. The menus were so robotic and lifeless, now it all feels like Mario Kart should







