I've seen Crystal Black, and don't really like it, it's a bit too glossy for my tastes, also you can't make it matte and get rid of the gloss.... Oh well, thanks for the link!
Well, with lion, it's more complicated, and the Mac theming community is still trying to get it's head around what's different in Lion and how it behaves. They'll figure it out soon though hopefully.
It's currently in dev stage for Lion, but I'd keep an eye on it if I were you.