• Geomancer (Elemental Shaman):
The new shaman talent, Thunderstorm, is a bit lackluster at the moment for instancing Shamans and solo. And with the tier 10 (46 point) shaman talent, Earth, Storm, and Fire, also being somewhat pointless for PvE, this build is one of the few that doesn't invest as many points as other classes might. The upswing of leveling Elemental is the massive burst damage taking down single mobs extremely fast.
• Theurgist (Enhancement Shaman):
This talent tree has extremely high DPS potential, low downtime, and a potent combination of melee and spell power synergy. The mechanics of Flametounge (imbue) and Lava Lash allow Enhancement Shaman in WotLK to break somewhat free of the highly rigid slow-as-you-can go double WF restrictions. An extremely popular choice for both levelers and instancing.
• Isangoma (Restoration Shaman):
In WotLK Shamans gained access to Riptide, a much needed HOT effect, which boosts your chain heal spell with a rather fast cooldown. Restoration is a very frequently seen build for PvP Shamans and will probably be popular on PvP servers. They are very capable healers, while still having the ability to interrupt enemy CC's or heals. The downside is leveling a Restoration Shaman is rather tedious and slow because they sacrifice a lot of DPS for an increase in healing.