the next release feature tag has been tracked into rawhide for next
fedora release. And unless there is a policy change in EPEL, its not
going to suiteable for there either. Look here :
https://fedoraproject.org/wiki/Features/ReplaceMySQLwithMariaDB

The bit that we are keen to drive towards is to bring this into place
now, for people who want to make the switch - or to try and see if we
can get a parallel install in place as well ( similarly percona-db is
being worked on too )

The EPEL 5 and 6 packages have been built in Koji - they'll probably be in the EPEL repos in the next 48 hours or so...

Parallel install looks like it'd have to be built by CentOS as from what I can see the intention remains upstream to replace an existing install still.