I find parties like that to be a waste of time and boring.
But that is personal preferences. I find actually thinking to be more fun. Which is why I spend most of my time thinking about things.
Anyway back on topic:
Little Mac deserves a spot
Shulk I think does deserve it
As for Pikmin
We have 3 new main characters Alph, Brittany, and Charlie
Considering Lucas and Falco as secondary representatives I think one of these guys is getting a spot.
And with the addition of Flying Pikmin and Rock Pikmin, I know these guys can get a moveset different from Olimar.
As for Kid Icarus
I know Pit is staying but I also think Palutena might have a chance. Although one of Pit's abilities is because Palutena is helping him which might hinder her chances.
Also if Professor Layton has a chance it is as a Second Party developer. Layton has been on Nintendo platforms except in one Freemium game on the iOS/Android. I still consider Layton as a Nintendo series but I wonder if that single Freemium ruined his chances. The games popularity is huge especially in Japan, which gives him a boost but will it be enough?