My suggestion would be to check out PP8 there are lots of changes lots of ajax and all the css for a standalone is fully xhtml and css3 compliant. Yes there are still some tables but also lots of div ul and li elements. Remember the application also has to integrate with 20 different products so some template sets are geared to those other integrations.
The application is very streamlined. From what I remember about your sites you always hack your sites and use older code and getting you to update is hard. There is also with PhotoPost 8 a plugin system much like vb
where you can add code to display into various places in the application. I think that is a plus for you.
The best thing to do I would think is update one of your sites and see as it would be a big improvement over older code.