Probably this is old new to everyone interested in the subject but me, but I just discovered an excellent blog post written last year by Juno Books editor Paula Guran on the evolution of term "urban fantasy" & what it now commonly means to publishers/readers. I don't like this limited definition, for what was once a useful term for a broader range of types of stories in a certain fantasy mode — but it is what it is. Guran's point that the current examples of the genre owe "more to the American hard-boiled detective genre than most may understand" is especially well-taken.
I have thought it strange that the term got attached to series books that so often use horror tropes, such as vampires, demons and werewolves, but, reflecting on it, maybe it does make sense, because those images have long since ceased to invoke the responses horror strives for, and seem to used in these paranormal detective series' for their erotic or romantic appeal.
The danger is when major publishing houses try to cram works that don't fit this very narrow set of ingredients into packaging that seeks to mislead the fans of the stuff into thinking its more of the same. When it isn't, then the fans are justifiably disappointed.