@Psycho: There is a major difference between R.O.B. and AGES.
AGES may be a "peripheral", but unlike R.O.B., there has NEVER been such a thing as "AGES" until Sonic and All-Stars Racing Transformed. R.O.B. is merely characterization of the robot "toy" itself, which has been done before multiple times prior to Smash. R.O.B. is not original to Smash. AGES is original to SaASRT.
Closest example would be Mr. Game & Watch, but even then, he had a base; all of the unnamed characters in the G&W handhelds. He merely is a representative of them as much as Yoshi is a representative of the multiple colored Yoshis from the Yoshi series (no, he is not Mario's Yoshi).
@Arcade: Captain N wouldn't really be an OG character, now would he?
@Diddy: Falcon doesn't count because he's from an established game series.