My problem with clones in fighting games is that one interpretation of the initial moveset will almost always outshine the other, and thus render the other character useless. On rare occasions, both the original moveset and the clone will be viable (Like Fox and Falco), but more often then not it's not the case.
With:
- Mario and Dr. Mario
- Marth and Lucina
- Pit and Dark Pit
In the meta-game I can almost guarantee you that one playstyle will completely overshadow the other. In fact, I will be surprised if it doesn't happen. Unless the balance in this game turns out to be really good (which would surprise me, considering how unbalance Melee and Brawl were) I don't think both Marth and Lucina will be viable. Most will gravitate to the other once the meta starts to develop.
Because of this, any miniscule of development time that went to these clone characters I would have much rather be allocated to somewhere else. Quantity doesn't equal Quality. Just because these "low-effort" clones pad the roster with more characters, doesn't mean they were a worthwhile investment in the end.
Let's not get too crazy now
. There's still a chance that we've seen the final roster. Sure, that chance has been minimized as of now, but it's still possible.
Outside of my bias, I think we're geared for at least one secret character we don't know about yet. If I were a betting man, it would be a toss up for either Wolf or Mewtwo. Hopefully even more, but I'm trying to keep my expectations in check.