Not that I don't totally disagree with the general principle of what you're saying, but I think at this point, if websites started using frames again and putting menus that don't move at the top again I think THAT would be a usability flaw as internet users
won't be acustomed to it.
It's really easy to get around. Hit the Home key and you're at the menu.
It seems sort of interesting to think about how websites could integrate into the browser though (context menus, skinning, etc).
It would be interesting if the browser took the items in ul's marked with id="navigation" and exposed those items in some
sort of index module for users to click.