That is, if you believe the listings for said games on the ESRB's website (linked above; screenshot below). I do, as news pertaining to the addition of other games heading to digital distribution channels like Xbox Live Arcade and Nintendo's Virtual Console have been leaked via ESRB listings in the past.
Please, please let this be true! If it is, that means there will be FOUR Ninja Gaiden titles on the 3DS (there's (apparently...unless it has been cancelled) an original Ninja Gaiden title in development for the little handheld that could). FOUR!
If this is indeed true, will you be purchasing any of these? I know for sure I will buy Ninja Gaiden II: The Dark Sword of Chaos (one of my all time favourite games). Ninja Gaiden arcade is a probable, but not certain buy. Depends upon the price. I'm not a big fan of it but it's decent. I'll probably skip Ninja Gaiden III: The Ancient Ship of Doom, as I don't really like that entry in the series.
P.S. As of now, the first NES Ninja Gaiden title (simply titled Ninja Gaiden) is not listed for the 3DS. I don't know why, and I hope that changes, because it's an excellent game, and even though I own it on the NES and the Wii I will still purchase it for the 3DS. It's not as good as the sequel that was released a year later on the NES, but it's a very good game in its own right.