Still in the works. When it is almost being released the developers will drop a message on the forum coming soon. with a specific time frame.
David i think they said it would be beta testing first when it comes out so they can still tweak it. We all know with any new addition to games. Someone will figure out some way to abuse it because they were able to see something the developers were not able to see or didnt think of. That is in every game with new additions usually. So if you see any issues when it comes out i am sure kano will be putting a thread on the forum labeled battle arena issues.
What do you mean "play tested on paper" ? Do you guys draw on paper funny pictures of game characters and fight with them? lol Sorry for the joke, i just couldnt let it slide lol