I filed Bug 17176 with the W3C a few days ago (my first on the HTML spec). The gory details are at https://www.w3.org/Bugs/Public/show_bug.cgi?id=17176
Basically, I'm arguing for a consistent cross browser string representation of the DOM structure because it addresses a current technical need as well as is a "good to have" feature.
See the complete discussion there. Some of you might be interested. :)