Anybody can suggest edits ( http://blog.stackoverflow.com/2011/02/suggested-edits-and-ed... ) without even registering.

Community wiki posts can be outright edited by low rep users, and higher rep users can edit any post.

The idea that a wiki is better for rapidly changing content is... odd, to me; it seems it'd be a wash at best. Then again I'm an SE Inc. employee, so perhaps I just don't see the difference.