Hey Michael,
I'd be a bit surprised if you could find positive, substantive conclusions that metaethicists tend to converge on. My impression is that there's a great deal of disgagreement in the field.
However, I suspect you could find convergence on negative issues--that is, there are certain views, or at least certain combinations of views, that they might all agree should be rejected. Since I don't know metaethics well enough, I won't try to offer an example, but I do know that this happens in other areas of philosophy. To take an example that's already been mentioned in this thread, I think the fact that most people who give serious thought to Popperian Falsificationism converge on the conclusion that it's wrong (even while many people who haven't thought seriously about it find it plausible) is some evidence that they're getting things right.
I wouldn't be surprised if there are substantive theories in metaethics that might seem plausible to people who haven't given them serious thought, but which philosophers have come to reject. If that's the case, then absent foundational worries about their methods, I think we should tend to think that their convergence is evidence that they're right to reject those theories. If we're interested in the questions that Eliezer posted, we should look at what philosophers have had to say about them--even if we're not likely to get the right answer this way, we may be able to eliminate some wrong answers.
Oh sorry, missed the comments after Robin's discussing the wisdom of consulting metaethicists about these questions. Suffice to say, Bob's right that there are some very compelling arguments against Popperian Falsificationism. They are compelling enough, in my opinion, that it's hard to think that its having fallen out of favor in the philosophical professional represents anything but progress.
Also, here's a relevant difference between consulting philosophers about metaethical issues and consulting astrologers and theologians about the issues they discuss. With astrologers and theologians, you (I suppose "you" refers to TGGP here, but I'm also describing my opinion on the subject) think there are fundamental methodological problems with the way that they come up with answers to questions--they rely on false premises, and use unreliable forms of reasoning. So, you shouldn't expect hard thought (which theologians, if not astrologers, have certainly engaged in) in those disciplines to lead to true beliefs. Since you don't think that your reasoning about theological and astrological matters suffers from these foundational problems, you should trust your own thinking on these matters over that of theologians and astrologers.
However, unless you have similar foundational worries about the methods used by philosophers working in metaethics, you shouldn't be similarly inclined to trust your conclusions over theirs. Unless you think there's something systematically wrong with the way they approach things (which it's hard to see why you'd think if you were unfamiliar with the literature), then you don't have any reason to think the effort they've expended in thinking about the subject is less likely to lead to the truth than the effort you've expended (after all, it's not your job. at the very least, you've spent less time thinking about the issues than they have).
I think these observations suggest a general lesson. If you're going to trust your own opinion over that of those who've spent more time thinking about an issue than you have, you should be able to identify some systematic unreliability in the methods that they use to think about the issue.
I'm sympathetic to Robin on this one. For people who are interested in thinking seriously about these questions, I think a good first thing to do would be to run a search for metaethics on the stanford encylopedia of philosophy (http://plato.stanford.edu/). If people like that, then it might be good to buy a book that would serve as an introduction to metaethics, maybe an anthology, or a textbook. I'm not familiar with much of the literature, but I can say that Michael Smith's "The Moral Problem," serves as a pretty good introduction to a wide number of metaethical debates, though it's not written as an introductory book. I'm sure the bibliographies on the stanford encylopedia of philosophy articles would also be helpful.
Bob,
Daniel Dennett, an analytic philosopher, makes a very similar point to one that you do in defending physicalist approaches to the philosophy of mind. He thinks that the idea that there's a special, hard problem associated with explaining consciousness is similar to the pre-20th century idea that there's a special, hard problem with explaining life, and that philosophers who posit irreducible mental substances or properties are no better than vitalists, who believed that appeal to irreducible vital forces was necessary to explain life.
Dennett is far from unusual among analytic philosophers in his physicalism. Some form of physicalism about the mental is almost certainly a plurality position among analytic philosophers, if not a majority one. While I'm sure there are other biases that analytic philosophers suffer from, I think the one you've suggested isn't a plausible candidate for a general problem with the profession.
Simon,
While I'm not sure what you mean by saying that most philosophers working in ethics think that morality is something "out there" I suspect that on a suitable clarification of "out there" it will turn out that lots of constructivists, quasi-realists, and anti-realists of various varieties will not think that morality is out there.