Well, here's a piece of very good news, although still no 100% confirmed in my opinion. According to OMGUbuntu and a variety of other sources from the just-concluded Ubuntu Developer Summit, the decision has been made to drop Mono from the base Ubuntu 12.04 distribution - whether it will remain in the repositories is not yet clear. That makes me personally so happy! Mono is covered with the stench of Microsoft, and I will be happy not to have to run my "nomono.sh" script as much in the future.
Flushing Mono down the toilet, where it belongs, will require removing Tomboy (no loss), and either replacing Banshee or modifying it to remove Mono dependency. Well worth the effort.