Sylvain and I have discussed recently his discomfort with Web browser state of the art in the age of AJAX (to use a grand term, even though I strongly believe that AJAX is nothing but an incremental gathering of conventions rather than anything new and special). He has gathered his thoughts in a blog posting "The chicken and egg problem". I posted a comment, but I thought I might copy the comment here as well.
[Let me summarize] in brief my reasons for thinking that the current system is not broken, and that we do not need to change anything fundamental about browsers.
First of all the basic semantic of "link history" in a Web browser has not changed since the Mosaic days for a very good reason: it is empirical to HTTP, REST and all that. At each point a browser is at a particular resource, and it moves from one resource to another according to actuation of simple REST verbs. Within each resource the browser can do all sorts of complex things, including showing animations (Shockwave, SVG, etc.), providing mini-applications to the user (Java applets, Flash, AJAX, etc.) and more, but the resource has not changed. The boundary of resource is defined by the service provider, and the browser simply reflects that in the history, URL bar and other features. I don't think the back and forward buttons should be overloaded for any operation within a resource. They should not be used as hot buttons in Flash apps or in AJAX apps. This violates the layering that is so important to the success of the Web.
If service providers want to provide navigation within a particular resource, they should do so within the application, and not at the REST level. I want my Front office app to have an "Undo" button (which makes much more sense than "Back"). [Why do I need chameleon browser chrome when I can just do
<xforms:button id="undo"><xforms:caption>Undo</xforms:caption>...</xforms:button>?] When I click browser "Back" I want that to exit the application and go to the previous resource.
IMO People think they have trouble with the back button and Ajax because they do not appreciate protocol layering very well, and because the AJAX tools do not yet help in this understanding. I think a better understanding of this layering and better tools are what's needed, not a major redesign of the browser idiom.