Thinking about this some more, what would probably help to make Xara generated markup easier to use with jQuery would be the ability to control certain tag attributes.

jQuery relies on being able to look through the markup for the bits of the page that you want to manipulate. This would be made easier if Xara was to allow you to put 'markers' in the markup to help identify what your after. By this I would mean the ID, CLASS or even user-defined tag attributes.