Of the twenty free games current 3DS owners are getting in exchange for having bought the system at full price, ten are NES titles, and the rest are Game Boy Advance games. Nintendo hasn't said what each individual "Ambassador program" game will be yet, but we have two more to add to the confirmation list.
Super Mario Advance 4: Super Mario Bros. 3 (I really do hate this naming scheme, even years later) and Kirby & the Amazing Mirror are both set on the GBA side. That means five NES and three GBA titles are still a mystery.
I'm fairly satisfied with the line-up so far, though some of you are undoubtedly taking this whole thing far more seriously. Just give me a Fire Emblem and some Advance Wars lovin' and I'll be content.