Wikimedia Bugzilla is closed!

Allow users to indicate authoritative users.  When accessing an 
article, the changes made since that authority last edited the 
page (major edits only?) in an unobtrusive way (1).  For 
instance, if the last time the authoritative author editted "the 
sky is blue" but changes since then have changed it to "the sky 
is green" the changed text would be in red.

Users would overtime build up a list of trusted authors which 
they could share with other users (2).

The benefit would be each person's list of trusted authors (1 
from above) or users whom they trust indirectly (2 from above) 
would reflect their choice, and not some central authority.  
Sort of a web of trust from encryption software.

This would probably be too much load for Wikipedia, but I could 
see value in a corporate or smaller environment.