To those who said there hasn't been much of an ad campaign (I forget who, and am far too lazy to go back and find the posts to quote them), I obviously can't speak for other countries, but over here in the UK, maybe it's just been me but post watershed ad breaks seem to be littered with LA Noire commercials, so they certainly seem to be pushing it hard here.
Anyway, Red Dead turned out to be a surprising juggernaut in terms of sales, so I see no reason for this not to do similarly well. And seeing as I loved that and GTA IV, and given that the whole concept of "here's a body, find some clues dipshit and figure this out already, retard" (I'm not paraphrasing) is exactly the sort of thing I enjoy, I'd be very surprised if I didn't feel the same way about LA Noire. But we shall see. Although I'm too lazy (again) to have pre-ordered, when I bought Red Dead, my local Game store had gotten too many of all the pre-order codes and gave one to me for free. Touch wood if I can get there from work before they close on release day...