Firefox will warn about out of date Flash Plug-in

Starting with versions 3.5.3 and 3.0.14, FF will warn users if their Adobe Flash plug-in is out of date. This will only happen after the browser is updated. Instead of the normal “You’ve been updated..” screen, you’ll get a warning that Flash is out of date.

If you follow security issues in Windows, you will know that Flash has become a favorite target of hackers. Since they estimate that almost 80% of folks have out of date versions, they decided to try to be proactive.

http://blog.mozilla.com/security/2009/09/04/helping-users-keep-plugins-updated/