Humanizing features
Many readers of wikis are still unaware that the site is created by people just like them. Some people still report concerns that they've "broken the site" when they accidentally enter edit mode. There are many small changes that can be made to the reader experience to show users that articles are things that change, grow, and are refined over time by people just like themselves.
Some ideas so far
editTimestamp position modification: Show the last editor to contribute to an article with link to change history and user page (currently in mobile beta)
Visual history : Visualise the edit history of an article so you can playback or scrub through the building of an article (extension of work by community member jeph, originally a 2005 idea by IBM)
Top editors: Show the editors with the most contributions to an article overall and in the last fixed time span with links to their profiles
Visitor Velocity: Visualize traffic to a page so that users can see how it changes over time, especially interesting for new or current event articles. Link this to the Visual history.
Critical reading: Encourage readers to request/check/provide citations by (a) making it easier to do so, and (b) indicating the user that requested/provided the citation.