A couple of notes on elemental farming- the price of eternal fire has gone through the roof, so I figured I'd share some elemental farming spots. Sorting by count simply tells you where people are statistically most likely to farm. It doesn't mean these mobs are always camped. it just means that farmers have had good enough experiences there to farm there regularly. Typically that means fast spawning weak mobs that can be AOEd down.
Of course, life, shadow, and earths normally come from gathering skills so its not worth the effort of grinding them from mobs. The price of these on the AH is usually low enough to farm something else and use that money to buy them.
For eternal water, Frozen Earths in Zul'Drak drop these, and as a bonus to miners, sometimes mining their corpse gives crystallized earth. If crowded out, try Crazed Water Spirits:
For eternal air, check out Stormriders: As with most storm peaks mobs, they also drop relics of ulduar so there's good money to be had. If you want to kill more mobs faster with a slightly (about 6%) lower drop rate, try the Steam Rager. It is a much lower level, and respawns faster.
All of these areas can give you between 10-20 eternals an hour, so depending on market prices, can earn you 100-1000G an hour. If the price of eternal fire remains at 40+G this weekend, take advantage of it- farm eternal fires and undercut by just enough to sell quickly.
