Chat is pretty tricky to get right and moderate, we have a bunch of other social tools / additions to get to first though. Who would you be looking to chat with? Friends, meet new people? Forums should hold us over for general discussions etc and people can always break off into separate chat groups through other alternatives outside of the app. For myself, one thing I am currently missing is being able to interact with people on track comments. That can be solved through threaded comments and/or mentions on track comments that could fire a notification to the player mentioned. Right now I am leaning towards mentioning in comments, would provide a good "taunting" mechanism when beating people on the world leaderboard
a chat would be cool but then there's a lot of things on how the chat can get bad but it might be good. So at this point in time i guess there should be a integrated chat
I think the chat will just be distracting and lag the actual game.. Just my opinion though.. I like the comments and forum