The first zone is The Jade Forest. I covered this zone in my last gallery about the Mists of Pandaria, but Blizzard made several changes to the opening quest chains, so I thought I'd point out some of those items.
First, instead of crash landing in Pandaria and having to immediately fight off the Hozen (a race of sentient chimps), the initial Horde battle is from your gunship attacking this temple the Alliance have commandeered. The battle eventually moves to the ground, where you meet a Pandaren for the first time. (In the initial Beta, you did not meet the Pandaren until after the first few quest hubs.)
Screenshots of World of Warcraft game client by Wally Bahny for TechRepublic