I just received this passive and it seems to be a little weak. It increases damage to targets which you hit with fire damage... but the wizard doesn't really have many fire spells. All I see are meteor, fire hydra and the familiar. Maybe it could be useful if you have a weapon that adds fire damage? Any more advanced wizards have thoughts, insights or even build suggestions to make use of this seemingly interesting passive?
Actually, Conflagration increases all damage done to enemies, unlike Cold-Blooded which only increases cold damage.
That said, the Meteor (Star Pact) change still hurts a lot. I used to run a build where I alternated Meteor with other attacks, keeping Conflagration up for the benefit of my whole party....but it was only possible because of Meteor (Star Pact).