Nintendo wants you to enjoy some old school gaming on your 3DS. After offering the titles to their “Ambassadors” (early adopters of the 3DS), it appears that the titles will soon be available to everyone. The Japanese eShop already has listings for Zelda II: The Adventure of Link, and will get Super Mario Bros. next week.
This still leaves the Game Boy Advance titles as “ambassador” specific, but those just came around two weeks ago. We could see those hit the market shortly as well, but there is no word on exactly how long it will be.