To determine the types of structural differences I'm interested in capturing, writing an XML-based diff tool (if one doesn't already exist), writing XSLT to consume the diff tool output + the document and produce a temporary (i.e. diff'd) document with the revisionflag attributes properly set, and use whatever stylesheets are most appropriate for rendering the differences.

Does anyone see any problems with the above proposal (other than the challenges of writing a tree-based diff tool that produces output suitable for an XSLT stylesheet to properly set the 'revisionflag' attributes)? Does anyone have a simpler suggestion that'd still meet my requirements? Is anyone aware of some subset of this solution that's already been implemented, besides the output stylesheets?