What kind of bugs me about the trailer is the fact they revealed her as Chrom's daughter. In Fire Emblem: Awakening your not suppose to know that information until Chapter 13. I heard that they announced that she would be a clone character. It sort of makes her a spoiler clone character and that bothers me. I have no other problems with her as a character in smash though.
That's a fair statement, but it's the fact Lucina can be considered a spoiler character and a clone character. Shiek may have been a spoiler, but she was not a clone as far as I can tell. While Dr. Mario is a clone, but did not really spoil anything.
According to an OVA, Marth's last name is "Lowell" - assuming that goes for game canon (Because Marth was turned into a wimp apparently in that OVA) and it hasn't changed for 2000 years, that would make her name "Lucina Lowell" - it's alliterative! The funny thing is, Lucina has a friend named Inigo. And yes, people have been quick to make Princess Bride jokes about him all over the place.
When it came to FE reps, the original hero along with the recent/newest hero would join Smash. In Melee, Roy was in to promote Binding Blade in Japan. In Brawl, Ike was in to promote his sequel. Although his POR outfit was used instead, RD would be used in SSB4. (BTW not what I meant)
In SSB4, Awakening was the latest installment and used two characters. Chrom was one of the cover heroes but was the main guy. However, the other two heroes got in instead.