Well, it's a quite a late response, but it ought to be. After Ubuntu has shoved Mono down our throats for quite a while, they have decided to retreat from it. As of Ubuntu 12.04 there will be no more Mono on the default install CD.
I want to curse Ubuntu Dev's for their actions so far, but their decision to drop Mono, for what ever reason, is a considered a blessing by me. I might even give it a spin again in 12.04 after about 2 years of not touching Ubuntu.