Security Policy of backported software

[progress at alphalink.com.au]

In reference to the following thread 

http://ubuntuforums.org/showthread.php?s=19795d70673e4b282daf288ccb944f30&t=1012712&highlight=life+after+backports

What happens to the security status of all the Backported software?
Does the Backporting team supply security fixes for backported versions
of the Gimp, etc, for the lifetime of your *ubuntu version?