It should be like Tribes 2 or Red Alert 2 multiplayer actually. Were you have to register to play online and you get great integrated stuff like in-game e-mail; buddy lists; player search; chat; forums etc etc.
It would be so easy to use and really fun.
I don't know what multiplayer in Quake 3 is like but in AA it should be like what I just said and more.
they arent too user friendly , you cant change the size of the chat window . the rooms are only listed with limited description . plus an advantage of the browser not being ingame is that you can hang out in the rooms and surf the net and listen to music or something instead of being stuck inside the game's browser .