The fact Ike is returning pretty much guarantees none of the Star Fox characters are getting cut now. This roster would have been decided during Summer 2012, when Awakening had sold over 400k in Japan, but hadn't had a Western release yet. At this same time, Star Fox 64 3D sales were over 500k worldwide, so Star Fox and Fire Emblem would have been pretty similar in popularity when Sakurai was making his decisions. If he decided at that time Fire Emblem would get 3 characters, then Star Fox is certainly keeping its 3 characters.
Also nice to see Ike with his Radiant Dawn design since it fits him as a heavy weight fighter better now. My guess is since Marth is the lighter weight, faster swordsman, and Ike is the heavy weight, slow swordsman, Chrom will be the medium weight medium speed swordsman.
Of course I do like the idea of the My Unit character from Awakening being use to represent that game instead of Chrom. Since the My Unit represents the player, that character could be considered the main character of Awakening as well. If Sakurai decides that 3 blue haired sword users from Fire Emblem is too much, then the My Unit could be an interesting surprise with a Villager options to choose several different Male and Female designs.