Leia barely beating Padme makes me feel an upset by R2D2 is that much more possible. We'll see soon enough.
Like I said, R2 is basically a puppy -- you can't beat a puppy. I think Yoda will win the light side, but I could see R2 putting up a big fight. Honestly if R2 didn't make cute noises, and had vocals similar to C3PO it wouldn't be half as popular.
Mother vs Daughter (Leia/Padme) Son vs Father (Luke/Anakin) That would be to generic but more than likely would happen. I would wanna see Vader vs Yoda.
Han and Luke failing to make it to the elite 8? WTH? I know their matchups were tough, but at least expected better from Han Solo.
I don't recall Vader and Yoda ever meeting in the movies. I suppose R2 won't upset Yoda. Unless Yoda breaks a femur bone or something (too soon?)... but will still win...
I figured R2 vs Chewie would be close. Yoda vs Vader makes sense. (I voted for Vader, I'm unapologetic)