These past few days I have been playing around with a few Bright Wizard specs. I tried all three mastery trees, and I think I finally found one that works for me.
Initially I ran with my old spec of Conflag with a mix of Immo. It worked ok, but I didn't feel like I was really killing anyone. It felt like AoE wasn't like it used to be where you could blow up ten people at once.
My next spec I tried was Incineration with a mix of Immo. I once again didn't like it too much. It feels like I am always stopping, and waiting forever to cast one spell. I hate being a sitting target while trying to dps someone else down.
My last spec I tried was full Immo with a mix of Incineration. I love it. Almost all my spells are instacast. I like Withering heat because it causes damage from start to finish unlike in the other trees casting time is wasted dps.
I like to start my spell rotation with Nova, Ignite, Boiling blood, Detonate, and Playing with Fire, and finishing them off with Withering Heat. It really seems to work very well. I am able to even kill tanks with this spec pretty easily.
Right now I am running with the following tactics with this Immolation spec. I use Endless Knowledge, Fan the Flames, Devour Energy, and Ignition.