A problem with Wikipedia is that it only presents you with a snapshot view. Yes, the diff tools are right there but sadly people don't use them enough. I think it would go a long way to have a simple indication of frequently changing or recently changed content in the default article view (eg, content added in the last week highlighted in yellow, items removed in the last week in lined-out and grayed text). Something like this probably would not have prevented the problem presented in this article (which is apparently that some reporters are lazy), but it would be a big improvement, IMO.