I think that was EDI was/is/was supposed to be. Including the metadata (i.e. XSD) along with the data seems to conflict with the file being compact, and easy to be read by commodity tools. For many of my needs, where 100's of the same signature data is being processed, it's less about communicating the meta data with each file as much as asserting that the file meets some standard of metadata.

With this standard that is being proposed, how about the ability to either 1) include the metadata inline the file, or 2) reference a URI for the metadata?