I've been playing with this over the past day.
I had the idea of using the background images as the list item images (presently the navigation is a list), however that idea hasn't panned out due to the way in which browsers handle click events on list items (they select all content within the list item).
We could convert the background images to HTML image tags, however that would break existing themes.
I've decided not to tackle that as part of this issue, the reason being twofold.
- There are several other issues that can be combined here that require changes that would not work with other themes.
- Its too close to the release of 2.4 and such a change would not be accepted at this late stage in development.
Instead I have opened MDL-36016 to address the larger issue of redesigning the navigation and settings blocks.
I will leave this open for the time being and will close this issue when we know it has been addressed by MDL-36016.