57BA9C535AC4486C814902BA7537F2B4@Sealion" type="cite">

Actually, I don't think I have ever come across a real case 
of someone using XSLT with an XHTML input. 
    

I've seen many. Sometimes it's a custom screen-scraping application designed
to extract information from the XHTML delivered by one particular site;
sometimes it's general-purpose software for example to convert XHTML to
XSL-FO or office document formats; sometimes it's to transform the XHTML
into different XHTML, e.g. by changing the CSS styles in a systematic way,
change links, add copyright statements, or other similar mundane tasks.