Thanks everyone for replies. On Saturday I managed to update the server to
6.1. Or so I hope, I am not sure anymore. The update went smoothly with one
exception: SL .repo files got overwritten, and not only did "6x" revert to
"$releasever", but fastbugs was removed entirely. Had I not been vigilant, I
would be for quite a nasty surprise. Nastier even if I used third-party
repos with priorities, as priority settings would have gone up in smoke.
Can't say that I am thrilled by how this works...