Currently the private message layout is so you can have PMs on the left side of the screen and a chat room on the right side. If someone wanted to have two chat rooms on their screen with splitting each half dedicated for each chat room, then it becomes a hassle to switch back and forth from a private message screen back to the chat room. I was thinking that instead of dedicating an entire side of the screen just to PMs, you can have a pop up for chatting similar to current day facebook. Having the chat pop up from the bottom and being able to hide it back down will help eliminate the back and forth switching also keep things cleaner and having the option of turning on and off auto popups for messaging.