When Nintendo nonchalantly released images of The Legend of Zelda: Ocarina of Time on the 3DS, cautious gamers assumed they were likely a tech demo. However, several sites have reported that Nintendo executives are serious about the prospects of a full port.
According to Joystiq.com, "During the event, Zelda series producer Eiji Aonuma made its status as a game explicit when he discussed simplifying its menu system on the 3DS, in order to (among other things) make the Water Temple easier by allowing Link to add and remove the Iron Boots more quickly." Kotaku.com also reports that Nintendo executive Shigeru Miyamoto stated that the game is being "actively developed," although he stopped short of promising an official release.
Until Ocarina of Time 3D's release is fully confirmed, we can look at the pretty pictures: