This kinda happened in 2007... hence Words With Friends, FarmVille, etc. In retrospect it seems bizarre that random developers were able to publish updates with our own icons to the main Newsfeed.
I suppose I am speaking of a far more integrated portal for friends to play casual games together. More realtime than the newsfeed volley of 2007. If Facebook could create a really nice lobby platform and then have a handful of casual games, board games, card games etc. It would be very locked down and focused on friendly gaming, not the spamcity that was/is "Facebook games".