Hmm. "If you control an untapped land" is an interesting mechanic (assuming it's on more cards in the set). The opposite of "curve", it rewards you for not curving out. Making simple spells better in the late game is good.

Having been rereading Maro's article on Lenticular Design, though, I worry that newer players will just refuse to cast their spells until they've got enough land to get the bonus.

Do you think this card will be an issue, then?

Not this card, no. The mechanic might be a problem on other cards, though. If other more effective cards have "if you control an untapped land", that could encourage newer players not to cast their spells.

I think this should clearly be "basic plains". I'm not super thrilled with white land fetching in general though.

­Kor Cartographer is the flavor idea here.

I know that, and I'm letting it slide a little because Zendikar, but still in the abstract I'm not a huge fan.

All colors are allowed to fetch their own basic. White does it more than blue or red, even.