You don't define it as ability, you define it as ability plus some material goals themselves. Furthermore you imagine that super-intelligence will necessarily be able to maximize number of paperclips in the universe as terminal goal, whereas it is not at all necessarily the case that it is possible to specify that sort of goal. edit: that is to say, material goals are very difficult, cousin_it had some idea for the utilities for UDT, the UDT agent has to simulate entire multiverse (starting from big bang) and find instances of itself inside of it: http://lesswrong.com/lw/8ys/a_way_of_specifying_utility_functions_for_udt/ . It's laughably hard to make a dangerous goal.
edit: that is to say, you focus on material goals (maybe for lack of understanding of any other goals). For example, the koo can try to find values for multiple variables describing a microchip, that result in maximum microchip performance. That's easy goal to define. The baz would try to either attain some material state of the variables and registers of it's hardware, resisting the shut-down, or outright try to attain the material goal of building a better CPU in reality. All the goal space you can even think of is but a tiny speck in the enormous space of possible goals. Un-interesting speck that is both hard to reach and is obviously counter productive.
As Luke mentioned, I am in the process of writing "Responses to Catastrophic AGI Risk": A journal-bound summary of the AI risk problem, and a taxonomy of the societal proposals (e.g. denial of the risk, no action, legal and economic controls, differential technological development) and AI design proposals (e.g. AI confinement, chaining, Oracle AI, FAI) that have been made.
One of the categories is "They Will Need Us" - claims that AI is no big risk, because AI will always have a need of something that humans have, and that they will therefore preserve us. Currently this section is pretty empty:
But I'm certain that I've heard this claim made more often than in just those two sources. Does anyone remember having seen such arguments somewhere else? While "academically reputable" sources (papers, books) are preferred, blog posts and websites are fine as well.
Note that this claim is distinct from the claim that (due to general economic theory) it's more beneficial for the AIs to trade with us than to destroy us. We already have enough citations for that argument, what we're looking for are arguments saying that destroying humans would mean losing something essentially irreplaceable.