"Surprisingly we do it all the time, on animals, and we call it breeding. It is very successful"
Breeding is successful in some sense, but certainly not without its issues. For example, by breeding pedigree dogs we've left them with a number of genetic defects that are hard to remove due to the reduced gene pool, e.g. Dalmatian deafness, Bulldog respiration, King Charles Spaniel syringomyelia, etc...
Addressing the article, I find the idea of quantifiable intelligence to be one of the dumbest ideas we ever came up with. What does an IQ point mean, really? From my understanding, testing it basically boils down to using a specific subset of symbolic puzzles. Intelligence can be quantified numerically in the same way love can be quantified numerically, i.e. not at all, without losing the essence of what you're looking for.
Also, intelligence by itself is not a goal in its own right, it's the purpose to which it's applied that matters. If super intelligent people exist, what would we have them do? The same things we do but faster? No thanks.
Instead of wasting our time trying to group ourselves into categories, we should be looking to bring out the best of the talents we find in the people around us. That seems like a better goal than chasing a 1000 IQ person.