That's like a permanent "tutorial mode" though, why do we treat users as if they would never learn.
7/8's default theme aren't that much better; can you tell which of these are active?
http://www.groovypost.com/wp-content/uploads/2012/10/Windows...
http://i.stack.imgur.com/rFOQm.png
XP/Vista, much clearer "pushed in" effect for the active button:
http://mytechquest.com/blog/wp-content/uploads/2009/09/Iconi...
Windows 9x/ME/2K/Classic - very clear pushed-in effect for the active button:
http://www.howtogeek.com/wp-content/uploads/2009/01/613x178x...