Decided to upgrade the base MySQL backend today, but got into a world of pain, by following the last advice in /usr/ports/UPDATING.
That only updated the packages and lead to about 280 other ports and packages being over-written. Not good. Ended up having to Make Deinstall from the old Mysqlxx-Server and Mysqlxx-client ports and manually installing again.
But down now and hopefully some other lost dependencies fixed.