“As for this 3DS version, it was a timed demo, so one can only get so far in a Zelda game with such constraints. I poked around the overworld for a bit, and the only real discrepancy I noticed was somewhat softer visuals. The sprites definitely had a slight haze to them, though in a “cleaning it up” kind of way, rather than a “why is this all blurry?” foul up.”
GamesRadar recently got a change to try out the 3DS Virtual Console, which has Link’s Awakening and Super Mario Land already available, and it looks like they’ve made minor updates to smooth out the graphics, but have kept the game otherwise intact. While a bit disappointing for those who wanted an actual 3DS remake, you can’t go wrong with a downloadable and portable re-release of such a classic Zelda game.
The article also suggests that the Oracles games are also likely candidates for the 3DS Virtual Console, which would mean at least 4 Zelda Games available for the 3DS, even without including the inevitable new 3DS Zelda game (they’ve had at least one for every handheld iteration since the original Game Boy in 1989).