A mode much like normal page view (not source view),
but where the parts of a page most recently changed
are highlighted with a different background color, like a
subtle highlight marker (not reverse video or sharp
contrast color)
Much more useful than "latest changes" and individual
diffs; lets you use the page normally, but continuously
answers what you are usually most interested in: which
parts of this page are new, so I should read them again.
The highlight should "fade" towards the normal
background for less recent changes, until at a
specified "news-horizon" it just becomes normal content.
I have used such a scheme for marking new additions in
a dynamic music collection page, and with a color
chosen to not disturb too much, it is extemely effective
and intuitive (and several people who tried it said so
without me even commenting on the feature).
Age could be measured in time or in revision counts;
there are good arguments for both. One could even let
users choose, or one could "and" them.
For stylesheet compatibility, I guess the 'age'
shold snap to only a handful of named age classes with
fixed rederings specified by the stylesheet.
There could be a button to inspect individual pages in
this mode, or a user pref could let you browse in the
mode continuously (if the admin hasn't banned this for
performansce reasons).