A common practice on established, older wikis is to "touch" older pages by correcting grammar/spelling or adding a comment. The page will appear on RecentChanges and hopefully spark renewed interest. Sometimes, this is even used to subtly indicate GuidePosts to newcomers. Alternatively, one can also achieve PageChurn by whacking on RandomPage a lot, but that is highly personalized. Rather, one could use RandomPages to display a common set of random pages for the entire audience (TheAudience).
Another minor sort of PageChurn occurs on WikiWiki when someone cleans out RecentChanges. Pages you haven't seen in several days move right to the top of RecentChanges, where they're hard to miss before scrolling down to the bottom. Unless you're using Wiki:QuickChanges.
Vandalism and ForestFires can be turned around as positive events by eliciting PageChurns. Particularly overt damage, like blanking a page or adding a spam line, is often reverted without thinking, but semantic damage (undetectable without reading) will cause the PeerReview to reevaluate the page content perhaps enough to solicit new content. Similar to that, now that WikiSpam bots have finally been created, the spammed pages can also elicit PageChurn in perhaps a more random fashion than anything else one could create.
For conflicts, the joy of page churn is that editing pages to promote ForgiveAndForget or DissuadeReputation is, in the short term, totally counter-productive. However, the benefits kick in quite quickly, and the temporary remembrance can be useful for attaining closure.
A little game. If you come across this page and you haven't seen it on RecentChanges in a while, stop and increment this counter (thus churning the page): 31
Yes and yes. Random pages are interesting especially on this sort of mature wiki - lots of history in them and all that - but then again, I'm used to big huge communities with ridiculously large lists of RecentChanges (glances towards WikiPedia in particular) and, in my running around overturning the flowerpots here, sometimes I worry about HijackingRecentChanges.