I think this is rampant silliness. Obama grew up in Hawaii and it’s clear from what I’ve read that “Malia” is a fairly common girls name in Hawaii. So maybe he knew people named Malia growing up and liked the name? Sheesh, we’re in trouble if THESE are the things we’re using against our opponent.
I agree that this is not something to use against Obama, and it's not being used against him; this is just a discussion, not part of a campaign. God forbid a child should be involved in a political campaign. The discussion is probably just an expression of frustration over The Obamessiah's advent, and also with the tendency s many black people have to get their kids wacky names, which (not in this case, of course) become a badge kids wear that says "I come from a poor background."