I was after a bit different approach. More in line with MMS or MHTML. Packages of content would be prepared on served side and maybe a one package could contain all icons etc. used in site or in case of relatively static site, whole site including pages could be packaged. The internal URLs would then point to elements of multipart package.

At least in mobile world this could be useful. The initial load would be longer (creating data network connection and contacting the server takes quite some time anyway), but subsequent navigation would benefit.