From the video’s description:
“In God of War: Ascension Multiplayer align with the King of the Gods to be bewstowed powerful magic upon your weapons, and remind your opponents who is at the top of the chain.”
Zeus is just one of the four deities you can choose to align with, so expect more trailers for the other three to be released soon. God of War: Ascension comes out March 12, 2013. Pre-order now and you can get the Mythological Heroes Pack.