One feature I miss here is a fast* way to get all nodes that link to a particular node. That's something every scientific journal does (for example http://www.sciencemag.org/cgi/content/abstract/291/5507/1304#otherarticles
Why? Imagine you found a nice old node with Super Search. Then you click on the "Linked by" link (I suggest the same behavior as the readmore tag) and you get a list of newer threads. If you are lucky, then these threads cover newer Perl versions or recent CPAN uploads. In general it is a nice way to find related nodes.
Second, it would be easy to implement a "Most linked nodes" list. This way, we all would have a common place for all the classic nodes (What was the id of the "Homework" node? Or the "How (not) to ask a question?" one) instead of scratchpad lists.
*The only way I see how this is now possible is Super Searching for the node id. This is slow, uncomfortable and gets a few false positives.