I know this has been discussed before but this is always one of my favorite topics, its fun allows for shamans to be a bit creative, I wish list pretty much.
Here are my three ideas for our talent trees I figured you guys would like them ^^
Enhancement
Spirit of the wolf: Turns Shaman into a powerful wolf, much like druids and their Moonkin talent it would be a permanent buff that has a cost, while in this form the shaman can not cast any spells other then Storm Strike and Shamistic Rage (mainly for the damage reduction). In this form shaman would attack faster and would have a chance on hit to stun his enemies for 2 seconds and would also have increased attack power (maybe even gain attack power from agl like rogues?). The shaman will also gain 2 more special ongoing affects, immune to CC and also an aura that gives his party members a buffed WF (since he can't drop totems).
Elemental
Ethereal Form: Gives shaman the powers of ethereal... In WC3 this ability was used by the Spirit Walker unit, in this form he avoided all physical damage but took an increase in magical damage, although in WoW I would assume it would work differently. While in this form shaman would have increased power with damage spells by 20%, the shaman would also take 20% less damage from all types and would be able to resist spell damage push back, I would also give the shaman in this form a new spell of some sort, maybe a longer casting spell similar to star fire or pyroblast, something that would scale better then Lightning Bolt and offer higher burst but would cost allot of mana and take a long time to cast, maybe only trainable at 80? I am not sure how it would need to be balanced out maybe 10% increase damage instead of 20% or possibly make it so that in this form the shaman can not heal I am not sure, this is kind of like the shadow priest and their "Shadow Form" but I think it fits and would work nice.
Restoration
Spirit Link: This is another spell from WC3, it basically targets 2 friendly targets or group/raid members and links their health pools together, Whenever one takes damage the damage is split between both characters, whenever one is healed the healed health is split between both characters. In a perfect world this would be able to be casted on two tanks, making it easier for tanks, if one loses hate to the other tank the heals being spammed on the tank wont make the healers confused since it doesn't matter which tank they heal, and the tank will have basically double the hp and a buddy to taunt if something goes wrong. although due to game mechanics I would assume it would be shared between the tank and the shaman since I can not figure out how this would work any other way, but the affect is still more or less the same, the tank has more health, only down side is that if tank dies his partner will also die. For pvp I can see this being very useful, only thing I can think is that the linked players would need to stay within a certain range of each other and they would need to try to avoid aoe damage or it defeats the purpose.
Any body have any ideas of their own or ideas they have seen please share, and have fun with it ^^