FC doesn't include xmms-mp3, but xmms-mp3 depends on xmms. Hence,
the
upgrade of xmms will fail so as not to break xmms-mp3.
Beyond that, suppose that freshrpms does release xmms-mp3-42.1. In this
case, up2date COULD resolve the dependency and complete the upgrade -- but
to do so it would have to resolve dependencies across two different
repositories. Is it able to do so? (This XMMS example is the first one that
came to my mind, but it is easy to imagine more sinister dependency trees.)
The above is, in fact, the point of having multiple repositories.
-sv