Trivial? You have to define black, you have to define intelligent, and if the answer happens to be an unorderable set, you have to define _less_.
I'm unconvinced that they're measuring generated wealth by IQ, either. Most of the administered tests weren't IQ tests, they were educational tests. They measured the standard deviation of the _nation's_ mean, and then mapped that to an IQ. The correlation thus isn't a direct one between IQ and generated wealth, but rather between educational performance and wealth. More obvious, this one is.
Actually, the African countries aren't of serious concern. [1] Rather, the disparities between developing countries' current wealth and predicted wealth based upon current IQ have their uses:
http://finance.yahoo.com/q/bc?s=FEMKX&t=my&l=off&...
[1] The "are black people less intelligent?" question is actually pretty trivial, and has very few practical applications.