It seems that Nintendo has gone Fire Emblem crazy, as two of the three new characters officially announced additions to the roster are from Fire Emblem Awakening: Lucina and both male and female Robin. Caption Falcon was also teased toward the end of the livestream, as was Chrom.
For the former, no official eye catch was shown in the trailer but the official site confirms that he will be a part of the roster. As for the latter, it’s not clear as of now whether he’ll be a unique character or simply an alternate for Lucina, an assist trophy or a Final Smash.
Check out the awesome trailer, done in Awakening‘s graphical style, below. There’s also a nice screenshot gallery below that, including a lovely piece of artwork from Yusuke Kozaki.