I have been reading through the comments, and there does not seem to be much discussion about what IQ tests do well and what they do poorly. Generally there is an assertion that they are useful by some and an assertion that they are useless by others. As is typical in these cases, both sides are mostly wrong and only partially right.
Thinking about this, I believe there is one particular aspect of this discussion that needs more elaboration. Lets look at two ranges of the IQ test. The range from 80 to 120, and the range from 130 to 170. They are both 40 points apart and imply a wide difference in intelligence for those at the bottom vs those at the top of the range. However, the IQ test does much better (in my opinion and I suspect you can find independent literature to support this) on the range 80 to 120. Usually somebody with an IQ of 80 is not destined for a college degree and somebody with 120 has a good chance of finishing college. In this regard the test does fairly well. Whether it is actually measuring real mental talents of one type or another is a different issue.
Now, look at the range of 130 to 170. People with IQs of 170 are a bit different in nature to those who have 130. That seems fairly clear. But focused strengths in particular mental abilities are not well picked out and the IQ test seems to do a terrible job of predicting future grandmasters in chess, future professors at elite schools, future engaging storytellers, or even future great repositories of interesting trivia. Also when it comes to elite abilities, IQ tests at the high end of the range tend to discount the obsessive dedication that is required to become one of the best.
I think one of the issues is that IQ tests are good at finding deficiencies, places where somebody is lacking critical mental skills to learn what is required in our modern society, and does poorly at diagnosing elite mental talents. Those that praise the IQ test usually point out scenarios where the IQ test helped find people who needed additional resources to succeed. Those that criticize the IQ test tend to focus on how those with "genius IQs" tend not to necessarily do great acts that measure up to their numerical IQ score.
Take the relatively simple problem of determining potential skill at chess. Chess makes for a nice example because skill at chess is only somewhat coorelated with other mental abilities (making it possible to "isolate it" from other mental facets) and it is definitely measurable by competing with others. There is a clear cut state of "grandmaster" which all fairly accomplished chess players agree is a statement of real elite capability. It is (probably -- I am extrapolating on my own anecdotal experience) not hard to create a test to determine if somebody is going to play chess adequately and I suspect such a test is somewhat coorelated with an IQ test. A person with an IQ of 80 probably will never play chess that well, while a person with an IQ of 120 will likely learn to play the game adequately (counter examples are welcome). There are kids who clearly do not have much talent for the game and I doubt even focused study would help them. For them, learning how to mate with K and Q against K is a bit of a stretch.
But is it possible to create a test which will determine who is likely to be a future grandmaster (or even master) as compared to just playing "well"? I have recently been a chess coach for elementary school kids and there is one trait that I have determined that is coorelated with future ability. It is an obsessive interest in the game. I have kids who I thought were better natural talents, but they quickly fell behind those who made it their life mission to be better. In particular, I believe that an IQ test result of 170 is practically meaningless in predicting future great success in chess.
I use chess as an example, because I believe much the same can be said about any elite mental talent. Every time I hear debates about IQ, I ask myself, how well does it predict chess failure and how well does it predict elite chess success? I believe such a examination will produce results that are as valid as when the IQ test is used to predict future greatness in scientists and writers.