Here's my take on what the final charactor selection will be if the game does have around 40 charactors and how the franchises will be represented.
The thing is most of the charactors will be from the existing franchises that are in the game. Even though I agree it would be great to have alot more franchises represented, the current franchises shown in Melee are the most widely known, best selling series of Nintendo. Those are the series everyone knows about and so adding more charactors from those series are what's going to get the majority of the gaming population excited.
I'm going to say this right now, Mario, Zelda and Pokemon are all going to have at least two new charactors added to their series since those are Nintendo's top three. Every other franchise will have one new charactor, except Ice Climbers and Game and Watch since there's no other charactors to add from those series.
So if you break it down we're looking at 13 new charactors coming from existing franchises. Since Meta Knight and Wario have been shown that'd make 11 new charactors from existing franchises that we dont know about yet. So when you add all that up, but take into account they will be removing some of the existing charactors, plus the the 2-3 third party charactors, I'd say we're looking at only about 4 new Nintendo frachises being represented and I'm counting Pit as one. So that leaves 3 more charactors from different Nintendo franchises to be represented.
The mostly likely choices for those three would have to be Caption Olimar, an Animal Crossing charactor and an Advance Wars charactor since the Pikmin, Animal Crossing and Wars series are the top three most popular franchises from Nintendo that are not represented.