As I've just found out about this, and I've just recently been able to play Fallout 3 on my PC (as I've upgraded my computer), how's the progress going on this? As I see you do have a chat box system of some sort going.
When I wanted to build ontop of Fallout 3, a multiplayer world, it made sense to experiment with chatting in Fallout 3. But I am no longer planning on building multiplayer onto the game, rather I want to make my own game.