The next step in commercializing the Internet are micro-payments. Apple is the first commercial vendor to supply an API for that, in due time, I expect other game engine builders to supply such APIs.
Though I do doubt whether it's a good thing for the overall experience of on-line content. As a kid, I used to play a collecting card game, Magic the Gathering, which was great. The on-line treshhold for buying items is probably a lot lower, and games are pretty addictive. Bankruptcy by playing?
