Last modified: 2014-10-24 01:06:41 UTC
Currently the browser title bar (ie. the page title) is the same whether you're viewing the current version of a page or an old one. eg. instead of saying "Cheese - Wikipedia, the free encyclopaedia" it could say "Cheese [Revision: 18:26, March 17, 2009] - Wikipedia, the free encyclopaedia". Thanks.
On English Wikipedia there is a red "This is an old revision of this page" banner on the top of the page (but that seems to be on en.wp only).