I always just want to know: how do you propose to naturalize utilitarianism, thus showing your normative questions to actually be factual ones, thus showing that your normative claims are in fact grounded?
I would like to write an essay about that eventually, but I figured persuading PUs of the merits of HU was lower hanging fruit.
For what it's worth, I have a lot of sympathy with your scepticism - I would rather (and believe it possible to) build a system resembling ethics up without reference to normativity, 'oughts', or any of their associated baggage. I think the trick will be to properly understand the overlap of ethics and epistemology, both of which are subject to similar questions (how do we non question-beggingly 'ground' 'factual' questions?), but ...
http://valence-utilitarianism.com/?p=8
I like this essay particularly for the way it breaks down different forms of utilitarianism to various axes, which have rarely been discussed on LW much.
For utilitarianism in general:
For preference utilitarianism in particular:
See the article for more detailed discussion about each of the axes of preference utilitarianism, and more.