Edit: This is old material. It may be out of date.
I'm talking about the fictional race of House Elves from the Harry Potter universe first written about by J. K. Rowling and then uplifted in a grand act of fan-fiction by Elizer Yudkowsky. Unless severely mistreated they enjoy servitude to their masters (or more accurately the current residents of the homes they are binded to), this is also enforced by magical means since they must follow the letter if not the spirit of their master's direct order.
Overall treating House Elves the way they would like to be treated appears more or less sensible and don't feel like debating this if people don't disagree. Changing agents without their consent or knowledge seems obviously wrong, so turning someone into a servant creatures seem intuitively wrong. I can also understand that many people would mind their descendants being modified in such a fashion, perhaps their dis-utility is enough to offset the utility of their modified descendants. However how true is this of distant descendants that only share passing resemblance? I think a helpful reminder of scale might be our own self domestication.
Assuming one created elf like creatures ex nihilo, not as slightly modified versions of a existing species why would one not want to bring a mind into existence that would value its own existence and benefits you, as long as the act of creation or their existence in itself does not represents huge enough dis-utility? This seems somewhat related to the argument Robin Hanson once made that any creatures that can pay for their own existance and would value their own existance should be created.
I didn't mention this in the many HP fan fiction threads because I want a more general debate on the treatment and creation of such a class of agents.
Edit: Clearly if the species or class contains exceptions there should be ways for them to pursue their differing values.
Ah-ha. Okay. I hadn't thought of the trolley problem in those terms before. It's not very relevant to how I'm thinking, though; I'm thinking in terms of what actions are acceptable from a given starting point, not what end states are acceptable.
As to house elves: I don't consider humanike values to be intrinsically better than other values in the relevant sense - I disagree with Clippy about the ideal state of the world, and am likely to come into conflict with em in relevant cases, but if the world were arranged in such a way that beings with clippylike values could exist without being in conflict with beings with other values, I would have no objection to said being existing, and that's basically the case with house elves. (And I don't think it's intrinsically wrong for Clippy to exist, just problematic enough that there are reasonable objections.)
I would consider causing house elves to have humanlike values equally problematic as causing humans to have house-elf-like values, regardless of whether the house elves were human to begin with, assuming that house elves are satisfied with their values and do not actively want to have humanlike values. Two wrongs don't make a right.