I've been filling in the gaps in xcontents.dtx, and have a working package that more or less matches the documentation. The main thing I think from using the new packages it the error catching needs to be greatly improved. There is mention in xparse.dtx (I think) of putting help texts in \DeclareDocumentCommand, is that likely to happen? Similarly for an informal description of the arguments in \DeclareTemplateType. Are there any more thoughts on how that could be done? It would be James