Increases spell haste by x% if 3 or more targets are taking Fire damage over time from your spells.
Pyromaniac is a mage talent that increases spell haste if at least three targets are taking fire damage over time. This includes the DoT effects of Pyroblast, Living Bomb, Frostfire Bolt (with glyph), Flamestrike, Combustion, and Ignite. As of 10/13, the talent seems to be functioning differently than intended, as it only is checking for 3 fire DoT effects instead of 3 targets with fire DoT effects.
Edit
Patch 3.1.0 (2009-04-14): Now grants 17/33/50% of mana regeneration while casting. 
Patch 4.1.0 (26-April-2011): Talent overhauled. 
