Not really familiar with the Fire Emblem characters as I haven't played any games in that franchise, but I enjoyed using Marth and Roy in SSBM. And the announcements of "new challengers" are few and far between (this is actually the first new NEW challenger, since we've known about Wario, Zero Suit Samus, Meta Knight, Pit, and Snake since the 2006 E3 video), so this was a nice birthday surprise.
Thanks Nintendo!