Arthur Cover here. Years ago (1982) my friend J. Michael Reaves wrote a novel called Darkworld Detective, about a hero/detective named Kamus of Khadizar. In fact, John Shirley even wrote a sequel. Naturally Michael's book was a mash-up between noir and Leiberesque fantasy. The existential connection between noir and our hero's name should be obvious.
Then there's Glen Cook's long running series, which I believe began around the same time. So like most new trends, this one has roots that go back a long way, roots that some of the authors whose work is included in your discussion probably aren't even aware of.
Noir isn't a genre so much as it is a feeling, a philosophy, contained within a story with melodramatic elements. The movie Odd Man Out has an IRA sponsored bank robbery in it, but it's really about a dying man trying to find a place to die in an unsympathetic world. You can't get bleaker or more noirish than that.
