How does one deal with obsoleted updates from updates-testing

[Quentin Armitage]

My F-13 system produces the following output from yum list extras:
Extra Packages
glibc.i686                         2.11.90-14
installed       
glibc-common.i686                  2.11.90-14
installed       
glibc-devel.i686                   2.11.90-14
@updates-testing
glibc-headers.i686                 2.11.90-14
@updates-testing
gtksourceview2.i686                2.9.7-1.fc13
installed       
nscd.i686                          2.11.90-14
installed       

The glibc packages (including nscd) were in updates-testing, but have
been obsoleted, and so 2.11.90-12 is now the current version again. What
is the mechanism for becoming aware that a package that has been
installed through updates-testing has been obsoleted (especially since
the standard install of F-13 rc has updates-testing enabled)?

Bodhi doesn't even list gtksourceview2-2.9.7-1.fc13, so I can't see
where that came from, but the current version for F-13 appears to be
2.9.5-1.fc13.

Also, why are some packages listed as @updates-testing and others as
installed when all the packages are installed?