I have upgraded all of my own computers from Debian 6.0 (squeeze) now. I no longer use it myself at all. Some of my software already doesn't work on squeeze (particularly, yarn, which is part of cmdtest). I do not want to spend my time finding ways to support, say, the python-markdown library version that is in squeeze: I would rather make functional improvements than support ancient software versions.
I am hereby ending my support of squeeze in my own software. This means I will be removing squeeze from my apt repository on code.liw.fi, and will no longer test that my software works in squeeze, and will not be making packages for squeeze. (I am removing squeeze from the apt repository so that people don't wrongly assume it is being kept up to date.)
This change affects users of Obnam. Obnam was not part of the squeeze release of Debian, but I have maintained packages of it for squeeze on code.liw.fi.
If any of my software that is packaged in squeeze has security bugs, or bugs that would be considered release-critical by Debian, I will fix those, but only by making the minimal necessary change to the version in squeeze rather than backporting the current version. Debian is committed to support squeeze for several more months, and I will help Debian do that for my packages.