Eh, I foresee this sucking majorly for mages. You will no longer be able to cure a running tank in dzemael darkhold (or any other similar kiting situation), you're going to lose the option to dodge in the ifrit fight (also in the moogle fight if it has similar tactics), and you're going to lose the ability to run and heal yourself if you pull hate in anything. You'll have to stop and take and ass reaming while curing yourself.

They're doing a good bit to make all the classes balanced, but I don't see how this fits into that. No other class has to stop moving mid action or the action gets canceled. Final Fantasy XIV is too fast paced to have a limitation on movement like this.