If a group of people donated their bodies to cannibalism when they die for a group of cannibals to then consume them, I would have no problem with that. (I submit myself as an example of someone with moderate rather than extremely liberal views.)
I think the moral repugnance only comes in when people might be killed for food: the value of life and person-hood is so much greater than the value of an immediate meal.
Someone speculated earlier about a civilization of humans that had nothing to consume but other humans. Has it been mentioned yet that this population would shrink exponentially, because humans are heterotrophs, and there's something like only 10% efficiency from one step in the food chain to the next?
That's what was disappointing about The Matrix. If the aliens wanted to generate energy there would have been more efficient ways to do so (say, one which actually generated more energy than it required). I pretend the aliens were just farming CPU and the director got it wrong.
I think the moral repugnance only comes in when people might be killed for food: the value of life and person-hood is so much greater than the value of an immediate meal.
We already have moral repugnance towards the act of killing itself. I suspect that any feelings towards already-dead bodies exist independently of this. They may be rooted in feelings of disgust which evolved in part to protect from contamination (recently dead bodies can spread disease and also provide breeding ground for flies and parasites).
As promised, here is the "Q" part of the Less Wrong Video Q&A with Eliezer Yudkowsky.
The Rules
1) One question per comment (to allow voting to carry more information about people's preferences).
2) Try to be as clear and concise as possible. If your question can't be condensed to a few paragraphs, you should probably ask in a separate post. Make sure you have an actual question somewhere in there (you can bold it to make it easier to scan).
3) Eliezer hasn't been subpoenaed. He will simply ignore the questions he doesn't want to answer, even if they somehow received 3^^^3 votes.
4) If you reference certain things that are online in your question, provide a link.
5) This thread will be open to questions and votes for at least 7 days. After that, it is up to Eliezer to decide when the best time to film his answers will be. [Update: Today, November 18, marks the 7th day since this thread was posted. If you haven't already done so, now would be a good time to review the questions and vote for your favorites.]
Suggestions
Don't limit yourself to things that have been mentioned on OB/LW. I expect that this will be the majority of questions, but you shouldn't feel limited to these topics. I've always found that a wide variety of topics makes a Q&A more interesting. If you're uncertain, ask anyway and let the voting sort out the wheat from the chaff.
It's okay to attempt humor (but good luck, it's a tough crowd).
If a discussion breaks out about a question (f.ex. to ask for clarifications) and the original poster decides to modify the question, the top level comment should be updated with the modified question (make it easy to find your question, don't have the latest version buried in a long thread).
Update: Eliezer's video answers to 30 questions from this thread can be found here.