Thought I'd point out that while the download doesn't include A Link to the Past, it will have stages from it, Link's Awakening, and the original. This game was probably chosen to be the freebie because of how relatively short it is. My prediction: I'll start the game, play for fifteen minutes, get sidetracked for half a day, play for another fifteen minutes, get sidetracked for a week, eventually dabble in the new features, etc. Even though it's a Zelda game, it just doesn't feel like I'll be sitting down playing this for more than an hour, especially since the DSi/3DS's "stiff" buttons don't encourage prolonged playing periods. But hey, free titles come once in a blue moon, so I'm pretty darn grateful.
Apparently it's out in Europe, Japan, and a few others. The release for America will be in the next upcoming hours, so just be patient for those who don't got it yet.