Looks pretty nice. I don't think I will be using it on my PC since I'm quite happy with the dark theme, but it's perfect for my phone since I use that in bed (plus, it saves battery)
I like the gray accents. It feels like some places that are completely black could use a slight gray accent to contrast with the background, like the front page content, subforum/thread lists and forum posts. I get that black is kind of the point, but I think it would look better.
Would it be possible to set themes per device/browser, or at least have an option to default to black on mobile devices? Since the black theme is most useful on AMOLED screens.