Thanks to Robert Anderson (Feature Request ID: 2698921) you can now add attributes to the body tag in HTML output.
I wanted to use the http://code.google.com/p/google-code-prettify/ code highlighter and was able to get the script calls in using args.hdf/hdr, and use outputclass=prettyprint into the codeblock tag. The last thing was to modify the body tag to run the script when the page loaded. I modified the XSL to make it conditional, so it didn't modify the tag on pages that didn't actually need the script:
Here's what I learned implementing the tagging script in the DITA-OT build. In order to preserve the <script ....></script> syntax you have to put something, but a no-op, between the tags:
<script ....> </script>
It remains to be seen whether the script will run and collect page load data. It should, but...if I had a dime for every time I'd said/heard that...