RPM of the MySQL Community Server 5.1.56 GA are available in remi repository for RHEL and CentOS. See Changelog.
No RPM planned for fedora for which I provide version 5.5.9 which is now set as GA (stable).
This build use a spec file close to the one from f14. The InnoDB plugin (version 1.0.15 GA) is also available. The configuration file (/etc/my.cnf) contains the directives needed to enable it (except for EL-4). WARNING: before upgrading, a full backup of your databases seems mandatory (a logical dump using mysqldump for example). Simplest... Lire mysql-5.1.56