I wonder sometimes if we ought to mark non-live and non-article pages somehow visually, to flag up that they're not quite right. I'm not sure how - a red bar at the top under the pagename?
We do something similar when your try and edit an old version, it would make sense to do with same when viewing one. A simple change to [[MediaWiki:Revision-info]] making it bright red and putting a box round it would probably do the trick.