Just to put in my two cents for DK, he's a monster. He absolutely tears up Falco, Fox, and Falcon if played right. Man...some SCARY stuff, lol. Bowser's even a beast too, and I won't let anyone tell me otherwise.
About Marth and Roy returning, I could really care less for Roy returning to be honest. While Marth is awesome and one of my favorite FE characters, I'd love to see the Black Knight in the game. XP