From what I've played so far, I've found the following.
There are 4 worlds that you can go to, 1 is a capture the flag type area. I'm not sure how teams are broken up. An area for missions that is for players level 1-24, and another area that is for missions for players in the 24-40 range. I don't really know what the last one is, I haven't visited it yet.
There is a small area on the beginning map that is PVP, when you enter that area, it will tell you that you are entering it by flashing a message up on the screen, this area appears to be totally avoidable as well, I walked through it and didn't see anyone else.
The Chosen are able to recapture land, and once a melding tornado is defeated you can go into a bonus area to get more resources. There is a time limit in this area, and the map collapses if you don't make it to the exit in time.