>>and the actual implementation has completely stagnated for, what, at least a decade and a half?
>Who care about this? Email or newsgroups hasn't evolved much either..
There are really easily fixable UI flaws in the majority of web forums. For example most of them look like phpBB/vBulletin, and by default have teeny tiny little back and forward arrows for navigation, along with teeny tiny little page number boxes to jump to a page. The usability could be greatly improved simply by making these elements bigger (although you could probably think more interesting and powerful changes to the navigation pretty easily as well). But in all the years they have been around they have not done this simple change. The UI was designed in the 90s and it really shows (and hurts).