I agree with what seems to be the standard viewpoint here: the laws of morality are not written on the fabric of the universe, but human behavior does follow certain trends, and by analyzing these trends we can extract some descriptive rules that could be called morals.

I would find such an analysis interesting, because it'd provide insight into how people work. Personally, though, I'm only interested in what is, and I don't care at all about what "ought to be". In that sense, I suppose I'm a moral nihilist. The LessWrong obsession with developing prescriptive moral rules annoys me, because I'm interested in truth-seeking above all other things, and I've found that focusing on what "ought to be" distracts me from what is.