Magikrazy said:
I actually liked Dr. Mario's inclusion in Melee. I was like "Two Marios? That's interesting. Cool".
Personally, I'd be fine if we got another Mario.
And Dr. Mario may not be too far-fetched. He was intended for Brawl alongside Mewtwo and Roy but was cut due to time. In addition, he will not be an alternate costume. Sakurai says if a costume has even the slightest difference, they would become a separate character. Lucina is an example of this. She was intended to be a costume but sakurai tweaked her ever so slightly that she became her own character.
Because Doc would use pills and the tornado, as well as have a different fsmash, that's different enough for Sakurai to consider him his own thing. Sakurai even stated that Dr. Mario shooting fire would look odd.
Basically, don't be surprised if Doc ends up his own character again. It's either separate character or not playable at all. No alternate costume.