It would be extremely helpful to have a Metadata resource available as a child resource of the layer resource in GisServer map services, so that formatted metadata information can easily be displayed in web maps in a similar fashion to how it is shown in ArcMap when right clicking a layer and choosing Data | View Item Description. A REST URL looking like this would be great:
The response would be HTML transformed by the specified xsl for f=xsl (where style parameter specifies the xsl to use to transform the raw xml - options similar to those in ArcCatalog, including possibly custom xsl). The response would be the raw xml if f=xml. The response for f=json would be an object containing a string member called "xml" that holds the raw xml, and if style is specified, another member called "html" that holds the transformed html string. At the very least, adding an ItemInfo resource (similar to the one at the service level) for each layer would be very helpful so some metadata about individual layers can be imported using a tool similar to the one that imports metadata to the service from a layer.