For non-geeks, I would drop the word "intelligence", which carries too much baggage.
"Machines that can improve their ability to improve themselves can improve very quickly -- much faster than you might expect if you don't look at the math. And if a machine quickly self-improves to the point where it can change the world in radical ways, those changes might make us really unhappy or even kill us all. So we want self-improving machines to be 'Friendly' -- that is, we want them to be designed in such a way that the changes they make to themselves and their environment are good for humans. The upside is that a Friendly self-improving machine can also make the environment much, much, much better than you might expect... for example, it can develop improved technologies, cures for diseases, more reliable economic models, extend longevity, etc."
Come to think of it, that might be better for many geeks as well, who are not immune to the baggage of "intelligence". Though many would likely be offended by my saying so.
Taken from some old comments of mine that never did get a satisfactory answer.
1) One of the justifications for CEV was that extrapolating from an American in the 21st century and from Archimedes of Syracuse should give similar results. This seems to assume that change in human values over time is mostly "progress" rather than drift. Do we have any evidence for that, except saying that our modern values are "good" according to themselves, so whatever historical process led to them must have been "progress"?
2) How can anyone sincerely want to build an AI that fulfills anything except their own current, personal volition? If Eliezer wants the the AI to look at humanity and infer its best wishes for the future, why can't he task it with looking at himself and inferring his best idea to fulfill humanity's wishes? Why must this particular thing be spelled out in a document like CEV and not left to the mysterious magic of "intelligence", and what other such things are there?