Regarding the 3D effect:
I have no idea why Nintendo recommends keeping the slider at maximum when possible, because very few games are served well by that level of 3D depth. I find that keep the slider on medium or medium-low is ideal, because it allows you to move the 3DS without the effect spoiling as easily, and it does not hurt your eyes.
And guys, don't let your first impression throw you off the effect. It took me about a week to get used to the 3D, after which it's been really cool (although Ocarina of Time and Pilotwings are the only games where it's actually useful).
Regarding the possible games:
It seems that they're focusing on core franchises and making sure the games are diverse in genre, so I am entirely expecting something like Mario and Luigi (!!) or a Kirby game. We're already getting Four Swords for free, so I don't think they'd include another GBA Zelda game...Advance Wars and Fire Emblem are a possibility, but Nintendo might think they're too niche.
What I'm hoping is that the 5 games they talked about weren't the only ones worth mentioning, with the rest being crap. Actually, knowing Nintendo, they're probably gauging the response to the games they released to determine if giving away more good games is warranted or if they can just get away with giving us crap for the remaining games.