Well said. I'd go further:
The "is-ought" dichotomy is overrated, as are the kindred splits between normative and descriptive, practice and theory, etc. I suggest that every "normative" statement contains some "descriptive" import and vice versa. For example, "grass is green" implies statements like "if you want to see green, then other things being equal you should see some grass", and "murder is immoral" implies something like "if you want to be able to justify your actions to fellow humans in open rational dialogue, you shouldn't murder." Where the corresponding motivation (e.g. "wanting to see green") is idiosyncratic and whimsical, the normative import seems trivial and we call the statement descriptive. Where it is nearly-universal and typically dear, the normative import looms large. But the evidence that there are two radically different kinds of statement - or one category of statement and a radically different category of non-statement - is lacking. When philosophers try to produce such evidence, they usually assume a strong form of moral internalism which is not itself justifiable.
Do you believe in an objective morality capable of being scientifically investigated (a la Sam Harris *or others*), or are you a moral nihilist/relativist? There seems to be some division on this point. I would have thought Less Wrong to be well in the former camp.
Edit: There seems to be some confusion - when I say "an objective morality capable of being scientifically investigated (a la Sam Harris *or others*)" - I do NOT mean something like a "one true, universal, metaphysical morality for all mind-designs" like the Socratic/Platonic Form of Good or any such nonsense. I just mean something in reality that's mind-independent - in the sense that it is hard-wired, e.g. by evolution, and thus independent/prior to any later knowledge or cognitive content - and thus can be investigated scientifically. It is a definite "is" from which we can make true "ought" statements relative to that "is". See drethelin's comment and my analysis of Clippy.