Read the Releases Page for changes history, or Changes in MySQL Workbench 5.2.20.

The download site only provide RPM for Fedora 12 i386 and x86_64. My repository also provides RPM for Fedora 10, 11 and 13. Previous Fedora versions and ppc build will come for RC or stable version.

As always :

yum --enablerepo=remi install mysql-workbench

Of course, it was build with mysql-5.1.46-1

For a good packaging, it is necessary to use system libraries rather than bundled ones. Done for curl, libsigc++, boost, yassl (switch to openssl), ctemplate and mysql-connector-c++ (version 1.1.0, bzr snapshot 818, also available in my repo). I need more work for scintilla (if you are curious, compare the size of officials RPM to mine).

To be followed on MySQL Workbench 5.2.20 Beta 10 Available

Of course, this a beta version, but which become stable. This new version goes in remi repository, instead of remi-test.