Updated packages have been posted for testing:

ftp://ftp.scientificlinux.org/linux/scientific/7rolling/testing/x86_64/

An updated version of the 'sl-release' rpm has been posted to the
sl-testing repo.

This new version should resolve a surprising dependency loop in the
initial bootstraping of an SL 7 system.  This change alters the code
defining $slreleasever used for the official SL7 yum repos.

If no bugs are reported against this package by Dec 15, 2014, it will
be published as a bugfix.

Please test this package.

For more information on yum variables in SL7: 
http://ftp.scientificlinux.org/linux/scientific/7x/x86_64/release-notes/#_using_sl_yum_variables

You can install this update for testing via the sl-testing repo on
your SL system:
   yum --enablerepo=sl-testing update <package you wish to test>