You might think: Our moral duties to them would be similar to our moral duties to natural humans beings. A reasonable default view, perhaps. If morality is about maximizing happiness (a common consequentialist view), these beings ought to deserve consideration as loci of happiness. If morality is about respecting the autonomy of rational agents (a common deontological view), these beings ought to deserve consideration as fellow rational agents.
One might argue that our moral duties to such beings would be less. For example, you might support the traditional Confucian ideal of "graded love", in which our moral duties are greatest for those closest to us (our immediate family) and decline with distance, in some sense of "distance": You owe less moral consideration to neighbors than to family, less to fellow-citizens than to neighbors, less to citizens of another country than to citizens of your own country -- and still less, presumably, to beings who are not even of your own species. On this view, if we encountered space aliens who were objectively comparable to us in moral worth from some neutral point of view, we might still be justified in favoring our own species, just because it is our own species. And artificial intelligences might properly be considered a different species in this respect. Showing equal concern for an alien or artificial species, including possibly sacrificing humanity for the good of that other species, might constitute an morally odious disloyalty to one's kind. Go, Team Human?
Another reason to think our moral duties might be less, or more, involves emphasizing that we would be the creators of these beings. Our god-like relationship to them might be especially vivid if the AIs exist in simulated environments controlled by us rather than as ordinarily embodied robots, but even in the robot case we would presumably be responsible for their existence and design parameters.
One might think that if these beings owe their existence and natures to us, they should be thankful to us as long as they have lives worth living, even if we don't treat them especially well. Suppose I create a Heaven and a Hell, with AIs I can transfer between the two locations. In Heaven, they experience intense pleasure (perhaps from playing harps, which I have designed them to intensely enjoy). In Hell, I torture them. As I transfer Job, say, from Heaven to Hell, he complains: "What kind of cruel god are you? You have no right to torture me!" Suppose I reply: "You have been in Heaven, and you will be in Heaven again, and your pleasures there are sufficient to make your life as a whole worth living. In every moment, you owe your very life to me -- to my choice to expend my valuable resources instantiating you as an artificial being -- so you have no grounds for complaint!" Maybe, even, I wouldn't have bothered to create such beings unless I could play around with them in the Torture Chamber, so their very existence is contingent upon their being tortured. All I owe such beings, perhaps, is that their lives as a whole be better than non-existence. (My science fiction story Out of the Jar features a sadistic teenage God who reasons approximately like this.)
Alternatively (and the first narrator in R. Scott Bakker's and my story Reinstalling Eden reasons approximately like this), you might think that our duties to the artificial intelligences we create are something like the duties a parent has to a child. Since we created them, and since we have godlike control over them (either controlling their environments, their psychological parameters, or both), we have a special duty to ensure their well being, which exceeds the duty we would have to an arbitrary human stranger of equal cognitive and emotional capacity. If I create an Adam and Eve, I should put them in an Eden, protect them from unnecessary dangers, ensure that they flourish.
I tend to favor the latter view. But it's worth clarifying that our relationship isn't quite the same as parent-child. A young child is not capable of fully mature practical reasoning; that's one reason to take a paternalistic attitude to the child, including overriding the child's desires (for ice cream instead of broccoli) for the child's own good. It's less clear that I can justify being paternalistic in exactly that way in the AI case. And in the case of an AI, I might have much more capacity to control what they desire than I have in the case of my children -- for example, I might be able to cause the AI to desire nothing more than to sit on a cloud playing a harp, or I might cause the AI to desire its own slavery or death. To the extent this is true, this complicates my moral obligations to the AI. Respecting a human peer involves giving them a lot of latitude to form and act on their own desires. Respecting an AI whose desires I have shaped, either directly or indirectly through my early parameterizations of its program, might involve a more active evaluation of whether its desires are appropriate. If the AI's desires are not appropriate -- for example, if it desires things contrary to its flourishing -- I'm probably at least partly to blame, and I am obliged to do some mitigation that I would probably not be obliged to do in the case of a fellow human being.
However, to simply tweak around an AI's desire parameters, in a way the AI might not wish them to be tweaked, seems to be a morally problematic cancellation of its autonomy. If my human-intelligence-level AI wants nothing more than to spend every waking hour pressing a button that toggles its background environment between blue and red, and it does so because of how I programmed it early on, then (assuming we reject a simple hedonism on which this would count as flourishing), it seems I should do something to repair the situation. But to respect the AI as an individual, I might have to find a way to persuade it to change its values, rather than simply reaching my hand in, as it were, and directly altering its values. This persuasion might be difficult and time-consuming, and yet incumbent upon me because of the situation I've created.
Other shortcomings of the AI might create analogous demands: We might easily create problematic environmental situations or cognitive structures for our AIs, which we are morally required to address because of our role as creators, and yet which are difficult to address without creating other moral violations. And even on a Confucian graded-love view, if species membership is only one factor among several, we might still end up with special obligations to our AIs: In some morally relevant sense of "distance" creator and created might be very close indeed.
On the general principle that one has a special obligation to clean up messes that one has had a hand in creating, I would argue that we have a special obligation to ensure the well being of any artificial intelligences we create. And if genuinely conscious human-grade AI somehow becomes cheap and plentiful, surely there will be messes, giant messes -- whole holocausts worth, perhaps. With god-like power comes god-like responsibility.
[Thanks to Carlos Narziss for discussion.]
[Updated 6:03 pm]