It's up to you to pick between the two but here it is.

  Tauren Shaman:has 5% more hp i've heard, and has warstomp, this stunns enemies for like, 3 secs, and is on The HORDE! The horde (on Exodar server) i think has much better AH prices. Taurenalso look awesome. I had one and they rock.

  Draenei Shaman: HAs Gift of the Naaru, which heals overtime and increases every lvl, and costs no mana. Good at JC etc.

take orc.. they have tempory +50% ap skill and great lvling places

Gift of the Naaru is great early on, but it scales terribly.

I have both a Tauren and a Draenei I have found that the Draenei is easier to lvl with the Gift but the Tauren is better in pvp and pve solo with warstomp.  But just to clear things up since I created my Draenei I haven't logged back into my Tauren.  Draenei Own in Raid and Instances.

i went draenei only cuz i already have a horde mage,priest,rouge,pally,and lock