Ok, I have played ele shammy in some time now, and this how I see it.
Ele shamans do some nice dmg when you are protected by healers and melees, but without those you wont survive long...
But if played well and when you know what to do in certain situations, when to pop earthbind etc, you have a descent chance against almost almost any class, exept hunters they will rape you.. also purge and wind shear are nice.against healers and especially druid's HoT's. A nice bonus is that they can purge Agm effect.
And max out first aid is a must too, cus their healing sucks...
All in all a viable class though you might get ganked alot, but you will have fun, and i recommend you to try it