Not to mention the Assist Trophies in Super Smash Brothers Brawl and now three out of those have their own games (Saki, Starfy, Little Mac).
Captain Syrup finally came back after so long and starred in Wario Land Shake it (plus a cameo in Brawl if I recall correctly).
The Koopalings return (finally) to cause chaos
Pauline takes on her third lead role in Minis March Again and not only is she a main character but she CO-OWNS the mini mario toy factory along with Mario.
I'm very satisfied overall, and i'm sure that if there is a Smash Brothers 4 game we'll be seeing many of these characters there