Gunplay, performance, and resources.
The first shot at Planetside 2's beta was a pretty huge success, but complaints were made. Some obvious points about balance, resources didn't seem to matter a whole lot, and sometimes the game just chugged with less than optimal computers. John Smedley, on the forums, has outlined a few things that are going to be changed in the next few weeks. Among them, they're thinking about doing continent locking (preventing more players from spawning/dropping into zones for balance reasons), Esamir (the second continent), and other, smaller tweaks, like gun recoil and resource capturing.
Keep an eye on those patch notes, everyone.
Julian "Mirai" Williams