The article states that the final problem on the Boston globe redesign (meant as a proof of concept for responsiveness) was that image prefetching feature to sp

The article states that the final problem on the Boston globe redesign (meant as a proof of concept for responsiveness) was that image prefetching feature to speed up rendering which happens before html parsing. Thus they needed a way for browsers to parse that information separately ahead of time. I guess that it should be possible though for browser to parse a html fragment rooted on the picture tag, and then plug that tree back later on in the full document tree when it is constructed. Or is it simpler to search for picture/img attributes? Oh, there's this whole implicit tag closing business in html though...How do we know where to stop parsing a fragment? At least attributes values stops at the end of a string literal, or on a tag end. Perhaps that's the reason why they went for a dsl in attributes. I agree with you though, it's cleaner your way, and perhaps xhtml could use that approach in the future?