Thanks to the awesome help of the ZFS On Linux team (Darik Horn, Brian Behlendorf and Richard Yao) now all the ZFS On Linux patches required for DKMS functionality are now integrated into the EPEL 6 and Fedora DKMS packages. This means that in a future ZFS On Linux release a custom DKMS package will not be required for those platforms.
Please leave some feedback for version 2.2.0.3-20 if it works for you!