The changelog.xml generated by the subversion plugin yields entries like this for renames or copies:
<path action="A" copyfrom-path="/trunk/old.txt" copyfrom-rev="2847">/trunk/new.txt</path>

However the copyfrom-path and copyfrom-rev properties are ignored by the subversion log parser. If these were read by Hudson then the SubversionRepositoryBrowser could render these "new" files as renames and provide links to the appropriate diffs.