The only reason I'm interested in doing this is because of the huge pain it is for front-end developers every time there's a DOM structure/CSS change so you now have to go figure out where in the Javascript HTML building process you may have to update.
You must be doing it wrong.
The data coming back from AJAX should only be semantic data, i.e. stuff that doesn't change if only the layout changes. Converting the data to DOM manipulation is best left to a Javascript function defined in the master page itself.
