So the mystery is solved!! The villain for the new Star Trek movie is Spock's half-brother, Sybok! ...and this is why I think that;
A) His speed and agility/ strength
B) He can resist a Vulcan neck pinch
C) He has slightly pointed ears, since he's half human too, he retain more of the human the Vulcan side of him
D) In the original universe he was cast out of Vulcan for his beliefs, well what would happen to him if Vulcan was destroyed?? Seeks vengeance against the Federation and the crew of the Enterprise??

E) In the last trailer released, he hear the villain speaking about 'wouldn't you do anything for your family'...he's not speaking to Kirk, he's speaking to Spock! We also get a nice shot of Spock holding up his hand while another touches the glass between them.