Since I have been asked a lot, I decided to record a WotLK video to demonstrate how well Enhancement Talents (Flame Shock, Maelstrom Weapon, Lava Burst, Elemetal Devastaton, Shamanistic Focus and Elemental Focus) work together.
When you critically hit with a melee weapon, you reduce the cast time of your next Lightning Bolt, Chain Lightning or Lava Burst spell by 20%. Stacks up to 5 times. Lasts 15 seconds.
You hurl molten lava at the target, dealing 888 to 1132 Fire damage. If Flame Shock is on the target, Lava Burst will consume the Flame Shock, causing Lava Burst to critically hit.
22% of base mana, 30 yd range, 2 sec cast, 8 sec cooldown
Your offensive spell crits will increase your chance to get a critical strike with melee attacks by 9% for 10 sec.
After landing a melee critical strike, you enter a Focused state. The Focused state reduces the mana cost of your next Shock spell by 60%.
After landing a critical strike with a Fire, Frost, or Nature damage spell, you enter a Clearcasting state. The Clearcasting state reduces the mana cost of your next 2 damage or healing spells by 40%.
So in theory these abilities work well together and this video is just a little demonstration.
Flame shock + Melee Crits -> Instant Lava Burst -> Elemental Devastation -> Elemental Focus -> 0 Mana for next Flame Shock and -40% to next Lava Burst.