Because Mono 2.0 has been released today, I’ve added the following repo to my yast zypper repositories:
Index of /pub/mono/download-stable/openSUSE_11.0
I’ve learned a lesson: wait a few days, since this repo might be very busy which may block zypper altogether. 
Upon this time-out I’ve got a very naughty MS-DOS like error message:
Unexpected error: empty reply from <mono repo.>
Abort, Ignore, Over?
It’s better to skip the failing repository during the run instead of choking…