it's been awhile since I took psychology so I can't reference any good specific studies from the top of my head, but here: http://en.wikipedia.org/wiki/Iq#Criticism

The book EQ: Emotional Quotient is probably another good place to start...

I think most business "luck" is different from lottery luck

I don't deny the problems with the measure. I think a single number doesn't make much sense.

But my intuition is that you could fairly accurately rank people by intelligence, even if the quantitative number is ill defined.

People are different. Some are better than others in real ways. Many criticisms of IQ I've seen start with the a priori assumption that somehow differences mean lower worth. Reduced to absurdity, this leads to accusations of neo-eugenics.

I don't believe that any human is worth less than another, so I have no problem saying that some people are more intelligent than others when it is obvious.

Here is why it really matters: if we better study intelligence, we're well suited to learn to control it.

Significant artificial increases in human intelligence would be as important as the computer revolution.

I don't disagree with you here. I just don't think IQ is a good tool to use; unless you're just trying to predict someone's chances of earning a doctorate (nothing more and nothing less).