CEV and understanding recursive self-modification. Everything boils down to those two linked disciplines. The CEV is for understanding what we want, and the recursive self-modification is so that whatever is FOOMing doesn't lose sight of CEV while changes itself. I simply do not trust that anything will FOOM first and then come up with perfect CEV afterwards. By that time it will already be too far removed from humanity. This was, I think, a topic in Eliezer's metaethics sequence. It's the still unanswered question about what to do when you actually have unlimited power, including the power to change yourself.
Every option eventually boils down to a FOOM. This is why CEV and recursive self-modification must be finished before any scenario completes. AI is an artificial life-form FOOM, and may be friendly or unfriendly; uploading is human FOOM, and we already know that they're unfriendly with sufficient power; intelligence amplification is a slower biological FOOM; the first question asked of Oracle/Tool AI will be how to FOOM; and mainstream AGI is trying to build an AI to FOOM, except slower. The only non-FOOM related options are improving laws and institutions, which is already an ethical question, and computer security (and I'm not sure how that one relates to SIAI's mission).
The issue is that both of these are really hard. Arguably every philosopher since ever has been trying to do CEV. Recursive self-modification is hard as well, since humans can barely self-modify our ethical systems as it is. Though, as I understand, CFAR is now working to finding out what it takes to actually change people's minds/habits/ethics/actions.
Edit: But at the end of the day, it doesn't help one bit if SIAI comes up with CEV while the Pentagon or China comes up with uFAI. So starting work on AI is probably a good idea.
It's not just CEV and recursive self-modification, either. CEV only works on individuals and (many) individuals will FOOM once they acquire FAI. If individuals don't FOOM into FAI's (and I see no reason that they would choose to do so) we need a fully general moral/political theory that individuals can use to cooperate in a post-singularity world. How does ownership work when individuals suddenly have the ability to manipulate matter and energy on much greater scales than even governments can today? Can individuals clone themselves in unlimited number?...
Related Posts: A cynical explanation for why rationalists worry about FAI, A belief propagation graph
Lately I've been pondering the fact that while there are many critics of SIAI and its plan to form a team to build FAI, few of us seem to agree on what SIAI or we should do instead. Here are some of the alternative suggestions offered so far: