The last build has been buggy as hell, but I think it was likely just some errant code due to the Jade Forest revamp.
It seems that Blizzard felt the Jade Forest, being the entrance into Pandaria, was a little lite on giving the faction Pandaren some spotlight. They altered the entrance areas to now have Pandaren villages for each of the Pandaren disciplines. This means rather then a randomly constructed Alliance or Horde base in the zone, it will be us building fortresses among the Pandaren villages that share the factions discipline.
At least, that is how it seems, the zone is still offlimits and the only way we can see it has been Far Sight abuse and the new zone map.
For those that hate leveling, a new elixir has been datamined that increases EXP gain by 300% for 60 minutes. That puts it on par with the bonus given by RAF, though likely won't get the quest or dungeon completion EXP bonuses. No idea if it will be added to the game in the end, but right now rumors are it will be a new special recipe we can get through archaeology.
One of the big controversies is the inclusion of BiS (Best-In-Slot) raid gear to the Black Market Auction House. It only cycles the belt, bracers, and boots, and is hinted to be getting rings and necks, but won't have the actual tier gear. Some people hate it, saying it will force people to throw down loads of cash to be competitive in raiding or just reduce the quality or prestige of said items, while others support it, since it's the smaller items and will likely not cycle in the whole time. Personally, I think this was one of the biggest things needed on the BMAH. Without items that can essentially "expire" it wouldn't be a good consistent gold sink once the super rich exhaust all the mounts and pets.
Right now I have trouble playing, mostly because the lack of interface mods and the extreme amount of players causes almost instant respawn in some zones that overwhelm me. Add in the cross-realm zone bug that flags you for PVP and you get level 3 characters ganking all the level 90 using the MoP greens.