Did you have noticing that Brain Freeze make FFB crits as if the target where frozen ?
And now mastery will be a very welcome stat. It's will be hard to stuff with a 30% crit cap on the proc, a xx% haste cap on the bombs (depend on what you have choose) and a mastery that we will stack a lot.
I have made a test on a frozen target (deep freeze) with a frost bomb and glyph of fireblast, it's totally ridiculous. I think it will be changed rapidly because of pvp whine.
(I love the new orb skin)
edit> and we now know that it will be 543.4 stuff mastery to have 1 point.