With the move to dual-licensing with CC-by-sa, reusers should link back to the history.
I propose nice URLs for the history pages, so we don't end up with things peppered with "?" and "&" and "=" printed on mugs, travel guides, etc. e.g. http://en.wikipedia.org/history/Xenu instead of http://en.wikipedia.org/w/index.php?title=Xenu&action=history .
(Obviously, reusers *could* put up their own history page. But making compliance easier is likely to make it better.)
I filed this as an enhancement of Wikimedia's installation, rather that of MediaWiki itself, as it's mostly mod_rewrite config. It would of course be nice if the software did this by default when short URLs are enabled, but that may really be a further enhancement.