OS 3.0 preview event has already revealed two new developments that are going to change iPhone gaming: the ability for developers to sell downloadable content from within an app, and a peer-to-peer capability. According to Engadget's liveblog
of the event (which you should be refreshing obsessively
), the new In-App Purchase program will allow apps to interface with the iTunes Store from within, using a standard interface to sell DLC. Apple's Scott Forstall clarified that this is for paid apps only: "Free apps remain free -- you won't be asked to buy something in that app."