As troll u have improved attackspeed which can be nice in some fights when u have to nuke a healer fast or similiar situations.
Tauren has slightly more HP(HP is king in PvP) and a small stun for probably getting away from melees.
Orc has increased pet dmg(doing well if youre BM in the beginning) aaand
the +25% stun resist which outplays every other racial!!! you can resist rogue stuns, warr charges, pala hammers, other hunters improved dazed shots, tidal charma etc etc etc.
this racial is outstanding and playing as horde hunter is alrdy annoying vs all these freedom heroes. i really appreciate it having a chance to get away from enemies in some cases as orc :)
hope i could help u a bit with my statement
Greetings Icey