[boost] Named Template Params

I see that a Named Params library has been accepted into Boost. Great! Is this named template params or named function params? I've actually been working on a named template params implementation of my own so I'm particularly curious about what Dave and Daniel have done, whether it be for templates or functions. Is there an accessible page of documentation somewhere? There's been a named_template_params.hpp in the sandbox for a long time. What's going on with that? Is there general interest in a named template parameters library? -Dave