I note that WikiTrust will probably never be a default feature.

Quote from our press guy, who says it as well as I would:

“WikiTrust is one of thousands of extensions available within the
MediaWiki library. As with other extensions, including flagged
revisions, which has been the subject of quite a bit of attention
over the past few weeks, extensions are tested and evaluated by
members of the volunteer community before being implemented on any
of the Foundation’s projects, including Wikipedia. Many of these
extensions are part of ongoing research by outside developers and
volunteers who want to look at ways of improving the quality of
content on Wikipedia and other wikis using MediaWiki. When WikiTrust
makes its way through testing and analysis it may be made available
as an optional tool that Wikipedia users can activate through their
user settings. That timeframe has still not been set. The
Foundation is also looking at introducing a number of visible
trust/quality metric tools, which may include tools familiar to many
users, including ‘rate this article’ tools on Wikipedia pages.
These enhancements would be introduced in the spirit of letting
readers and editors better understand which articles, facts, or
edits need to be reviewed for quality and accuracy.”

Basically, cool idea, and the extension is available for people to use, but not one that’s planned to make a big change in the basic operation of Wikipedia in the near future