and the new race for alliance is not panda, damn.
http://en.wikipedia.org/wiki/World_of_Warc...#The_Other_Race

level cap is 70. this has been announced by Blizzard. go check on their site

Centaur can't go on the Alliance side as they are just pure evil creatures. they are the offspring of Cenarius' son and the princess you fight in Maraudon. Cenarius' son is the Keeper of the Grove (or at least just his spirit) you free after killing the princess. i'm guessing Maraudon is where the entaur were born in the beginning, thats why its a sacred place for them.

the Tauren were nomads because of the Centaur. if it weren't for Thrall, the Tauren would've all been wiped out by the Centaur in time.

a little story about Maraudon. the princess you kill is the daughter of  Therazane the Stonemother, one of the lieutenants of the Old Gods.

Akama pledged allegiance to Illidan, craving vengeance on the orcs and the demons that had corrupted them for the slaughter of his race. Using his stealth abilities, Akama and a band of his followers snuck into the Black Citadel and destroyed the magical energy generators which sustained the defenses of the Citadel, and then, he aided Illidan, Kael, and Vashj in the final attack on Magtheridon himself.

Kael and Vashj protected Illidan as he went about closing every interdimensional nexus on the plains of Outland. But as the fight went on, Kael discovered a camp of Draenei being assaulted by the Fel Orcs. Kael saved the camp by destroying the orcish base, and was greeted by Akama, the Elder Sage, who assisted Illidan and his allies by raiding other orc bases, distracting them as Illidan disarmed each portal in turn. The forces killed two blademasters: Mizgill the Fel Orc Blademaster and Gorgosh the Fel Orc Blademaster.