Create essentially a clone of Steam, but for mobile devices.

Integrate the marketplace, cheap games, achievements, and social elements into the mobile gaming experience.

Cost probobly cant get much lower though, the android market is alredy direct to consumer, but becoming the main "go-to" gaming application can probobly really raise the gaming abilities and experience on these phones.

Plus think mini games for your phone that can connect back to your PC version game to improve stats and etc. Similar concept to the console market years ago.