Ignoring all DLC/remaining character leaks, this is my hope:
There are 6 characters potentially missing in the CSS
1 of them is likely mii fighter, leaving 5.
I'd like Ice Climber, Lucas, Wolf to return, which leaves 2 left.
Since we got zero stuff about snake from today's leak (ESRB likely would have wanted snake's weapons highlighted), I'm not counting on him being one of the 2.
Hopefully one of the 2 is Mewtwo, which leaves 1 more - hopefully a newcomer. With everyone else we have, I'm even OK if that last newcomer is a clone.
Ideally, none of them are DLC (unless it's snake, he's worth DLC).