The latest horde-enhanced build for EPEL requires php-pecl-Fileinfo, which is not currently available in EPEL. I have filed BZ 592287 to request that package be built for EPEL, but in the meantime, horde-enhanced has broken a dependency and cannot be installed.
php-pecl-Fileinfo has been built for EPEL and is in testing, so this is now a non-issue.