the story plugin is now passed a hash containing the story's metadata

The metadata hash is also placed in $blosxom::metadata_hash{"$path/$file")

They're actually tied to invoke functions from the metadata module.
Right now STORE is unimplemented.
Allow stories to be formatted with markdown

The feature is enabled by including the field
    Formatter: markdown

in the META section.  (If you don't have a META section, add one.)

To do: global macros should be loaded and applied per-formatter, maybe?