"OS News reports that Debian developer Josselin Mouette got Tomboy accepted as a dependency for gnome in the next release of Debian (codenamed Squeeze). While that may seem like nothing big (except for the 50 MByte size of the Tomboy package), Tomboy requires Mono — meaning that Mono will now be installed by default. Apparently, Debian doesn't have the same concerns over using specifications patented by Microsoft and licensed under undisclosed terms that Red Hat does. Perhaps Debian doesn't believe that Microsoft might do something like Rambus did."
Source: http://linux.slashdot.org/story/09/06/15/1251228/Mono-Squeezed-Into-Debian-Default-Installation