Mega Tyranitar is on the left and Mega Aggron is on the right
they also revealed the artwork for Mega Kangaskhan(Left) and Mega Gengar(Right)
I am so happy that Tyranitar got a mega evolution, he's my favorite Pokemon and he's exclusive to Y so WOOT im getting Pokemon Y for sure. And also, 1 DAY remains until X and Y are released
Welcome to the Battle Tower. - Palmer