Along this line of thought, checkout AxKit. In a nutshell, it's an application framework in which you can 'bind' or map (a gross generalization) html/xml tags onto Perl modules ('taglibs'), thus keeping your logic seperated from your look and feel.

While the designers may need to be familiar with XSLT/XSL, they also get the chance to be a programmer in ways that most WYSIWYG editors and non-programmers can deal with. I can get anyone to write <cart:add item="SKU123" quantity="1"></cart> instead of intermixing Perl and HTML/XML.

-=Chris