If some of the new data mining is to be believed, the burnout looks like an on use mana dump for deep fire. Which I personally would love.
Name: Burnout (5 ranks, listing highest)
Description: Increases your spell critical damage bonus with all Fire spells by 25% but every time you critical with a Fire spell you lose an additional $44450s1% of your total mana.
Mix that in with Molten Fury and the 20% down on a boss would be nuts.
Other spells dug up:
http://urlshort.com/wotlk/site/talentlist.php
Name: Fiery Payback (2 ranks)
Description: Increases damage caused by Molten Armor by 20% and whenever you resist a spell the caster takes 50% of any instant damage that would have been caused. Damage caused by Fiery Payback will not exceed 50% of the caster's health.
Name: World in Flames (3 ranks, listing highest)
Description: If a Fire spell you cast hits 3 or more targets, the spell causes an additional 15% damage.
Name: Hot Streak (3 ranks, listing highest)
Description: Any time you score 3 spell criticals in a row, you have a $m1% chance the next spell will gain 100% increased chance to score a critical hit.