E.g. if you shipped an additional 10 MB of "data" with every browser, could you reduce the average image size on the internet by X% by leveraging that 10 MB?
(I have no idea; just an interesting thought exercise. Could make a cool masters thesis for someone.)
I suggest that you make a blog post or Tell HN about this and post it as a top level submission. I'd love to hear more opinions about this.
I understand the principle but don't understand enough of how it would actually work to speak for it as much as I'd want to.
Such a technique could also be especially useful for low bandwidth situations, most notably Paul English's proposed Internet for Africa effort, http://joinafrica.org/ .
If you're interested in this pursuit you should also look at SPDY, Google's suggested augmentation of HTTP. It would probably speed up the web more than better compression in many cases.