Metaethics is one of those fields where the wheels grind very, very slowly. I do think it's making glacial progess. But just as there has been huge resistance, over the centuries, to the idea that God does not exist, so there has been huge resistance to the idea that there are no objective moral oughts, in the strong sense of "objective" that ordinary folk and many philosphers seem to want. Then again, philosophy only ever makes progress in the face of strong resistance from people who are committed to saving the appearances/and or the traditional picture of the world.
The interesting question at the cutting edge of metaethics is what follows if we accept that morality is not objective. I.e., if we accept that the answers given to moral questions do not genuinely have the absolute bindingness and irresistible practical oomph that is usually assumed in moral debate. Richard Joyce captures the idea with two propositions:
1. Moral discourse presupposes non-institutional desire-transcendent reasons and non-institutional categorical imperatives. BUT
2. All genuine desire-transcendent reasons are institutional and all genuine categorical imperatives are institutional.
That's a technical way to put it, but I think it's pretty much a correct statement of the problem. There are reasons for action based on desires (or fears or wants or other such psychological phenomena), and there are imperatives contained in positive moral systems, systems of law, etc. But when we try to give a further reason to abide by the imperatives in positive moral systems, we'll end up appealing to psychological phenomena, not to something that is both (a) built into the external fabric of the universe and (b) itself imperative-delivering. There is nothing like that (and, I submit, even God could not be like that).
So how should we respond to this horrible suspicion - nay, truth - about morality? E.g. should we stop using moral language entirely (in a similar way to the way that many of us have stopped using theological language relating to "sin")? If so, how should (tricky word) we talk when we want to discuss what people ought to do? We seem to need some concept like that, and it needs to go beyond the idea of practical rationality (acting in the way that will achieve your own desires, etc). No one denies that there are oughts of practical rationality, but these are, in an important sense for this debate, subjective.
The guy to watch in metaethics is the above-mentioned Richard Joyce, who now teaches at the University of Sydney, and is embroiled in these debates. He's young, he's on the ball, and he's a much better philosopher than Sam Harris, at least when it comes to metaethical issues. Unfortunately, his new book is not likely to be a best-seller. (It's not even affordable to individual people; meaning that he and his co-editor couldn't find a publisher that was prepared to order a print run large enough to bring down the unit cost.)
I'm giving a paper on some of this in July, at the next AAP (Australasian Association of Philosophy) conference, but after thinking about it hard for the past several days, I'm now uncertain what I want to say. Though I'm not very impressed by the metaethical end of what Sam Harris is doing lately, and I think it's far behind the cutting edge of metaethics, I sympathise with him to an extent. This stuff is difficult. We've managed to adapt to the idea that there is no God and therefore no "sin". But it may be more difficult to adapt, psychologically, to the idea that there are no objective moral oughts built into the fabric of the universe or the nature of reason.
I'm now not sure what I think should be said about how we ought (that word again!) to use moral language ... given that morality can't deliver all the things that the folk naively assume it can. Some metaethicists argue for an eliminativist approach to moral language - such as we've adopted with "sin" language - but they will still need to use some kind of language to oppose (forcibly) such horrors as torturing babies or conducting extermination campaigns against despised minorities.
Even I balk at concluding that all positive moral claims are just false (like positive claims about "sin"). Strictly speaking, if we buy fully into moral error theory, that radical proposition might be correct, but it would sure be a misleading thing to say outside a philosophy seminar room!
I think, though, that the picture is a bit more complicated than this, and we need to tease it out, and probably to include some focused empirical study of what people think they are doing when they use moral language of various kinds. If any of y'all out there are working on this and interested in collaborating, let me know what you have in mind.