Thanks to Chris for this high level evaluation of the state of responsive images. THis post lays out descriptions pros and cons of each of the 3 foreseeable options: a new image format, a new syntax/html element or use existing technology.
Embedded Link
On Responsive Images | CSS-Tricks
There are three ways we can go about dealing with responsive s : 1) a new format 2) a new syntax 3) rely on existing hacks.