As part of some other work, I've enhanced my Transformer sequence for escaping and tagging XML code so that it works for comments as well, and added bolding to the code. I've updated the CSS file for the blogs to support this too, so this should look nicely syntax-highlighted:
<list type="numbered">
<item>cat
</item>
<item>dog
</item>
<item>fish
</item>
</list>