The libstdc++so7 package contains a preview of the GNU Standard C++ Library from libstdcxx_so_7-branch branch. It is considered experimental, and may in fact be completely unreliable. It is unsupported, needless to say. Don't rely on its ABI, or its API as it might change at any time. To use, invoke 'g++-libstdc++so_7' instead of 'g++'.
The libstdc++so7 package contains a preview of the GNU Standard C++ Library from libstdcxx_so_7-branch branch. ^^^^^ You can remove this extra "branch." -benjamin
This bug is squashed for the FC5 release-notes, added note to http://fedoraproject.org/wiki/Docs/Beats/PackageChanges
DOCS EDITOR ACK. All good, in the Wiki, which gets converted into the XML.