Here is the direction we are headed in for the interface. Instead of a circle indicating who's turn it is, we have a colored bar to the side of the board. The clocks will also be dimmed or bright based on who's turn it is.
Initially, Erik did not us to add the complexity of promoted queens, but I have always felt the need to have some kind of indicator. If the players demand it, I'm sure I can bring up that subject up again. If you ever need to make a queen trade, it's nice to know you're trading for 9, not 1. At the time, we had considered a simple + on the front of the queen, like so:
@ignoble, if there are a flip board icon next to each player to change to that players perspective, then you can always flip back with a single click. I know that is a bit different to how things work in live chess, but I think it would make sense to work that way.