I've noticed that Wikipedia now adds rel="nofollow" to user contributed URLs, so that [http://myurl.com/ website] becomes <a href="http://myurl.com/" rel="nofollow" >website</a>.
The rel="nofollow" attribute was (unofficially?) announced by Google in January this year, as a means to fight link spam in blogs, wikis and guest books.
But shouldn't rel="nofollow" also be used for the edit, history and diff links? These pages avoid Google indexing by having the <meta name="robots" content="noindex,nofollow" /> tag in their <head> section, but Google only sees that after having visited the page. The visits by Google to these pages are not productive, but still add load on Wikipedia's servers, and this could be avoided by adding rel=nofollow on the edit, history and diff links.
-- Lars Aronsson (lars@aronsson.se) Aronsson Datateknik - http://aronsson.se