It's possible. There are DS games which can do similar things by reading the GBA cart. Many PS2 games (Ratchet and Clank, Budokai, Tenkaichi, Naruto) rewarded your buying the previous game with free money at the start, discounts or lampshading that you had it before and giving it cheap. Fire Emblem on the Wii takes stats from your GameCube memory card to give a boost to the veterans from the last game. Surely a few combinations should be easy, even Brawl could store controls on the Wii Remote (and Miis in general which are just combinations as well).
Get, Play The Undersold Triforce: Z+W, NMH, Okami! PM of the SSR Board + Ninja of SATBK/SATFS forever