I think the Perl script is general enough to convert other stylesheets, but
not general enough to convert all stylesheets. 8^)
I didn't try to do slides because the special slides elements are not in
the DocBook 5 namespace. Converting that stylesheet would put them in that
namespace. While you could work with slides documents in that namespace,
such usage is not official and not portable.
The Perl script is in the DocBook SourceForge SVN repository if you want to
try it out:
/trunk/releasetools/makedb5xsl
Bob Stayton
Sagehill Enterprises
DocBook Consulting
bobs@sagehill.net