Comment 3 for bug 278946

Mono is ineligible for official backporting, as it's considered a "major framework" and at too high a risk of regression. The same rules prevent official backports for things like Python or Ruby. It's also hard to convince the Powers That Be to allow ~5 updated source packages producing ~100 updated binary packages which might affect the behaviour of several apps in the default desktop to land in -backports.

I can understand the desire to get ahold of the latest release, and I can assure you it's being actively worked on in Debianland, but the absolute key matter is that the *apps* which use the Mono framework are stable and reliable and working, and there's simply too high a risk of regression in pulling the rug out from underneath them.