I might have an idea for a fix on that. On facebook, when viewing a photo album, you can use the arrow keys to go left and right in the stack. I didn't think it did but I was proved wrong recently... the photo is the only thing that loads on the page, but the window's URL also changes, therefore keeping forward/back support without a entire page refresh. How is that done? Javascript I guess? And would that be acceptable if you could make it work?
Though my 2c, I'd rather have non ajax.