Though there may be a few rotten apples in the bunch (ahem, I Am Rich), what the App Store has proven is that iPhone is not just a device, a handheld, smartphone, or any other name for a mobile; it is an entirely new software platform. Steve Jobs is predicting "half a billion in sales...soon. Who knows, maybe it will be a $1 billion marketplace at some point in time," he told the WSJ this morning. According to Silicon Alley Insider, App Store sales are up to $30M, with the top ten developers netting $9M. Remember, Apple keeps a third of that for placing your app on their platform and marketing it through the App Store, as well as providing the tools to develop (if you haven't played around with the new iPhone SDK, you certainly should).
As these web and mobile applications become more readily accessible for the average consumer (not that iPhone consumers are average), they become more pervasive. Twitter, Loopt, Evernote, who cares how they monetize? Google didn't know at first either. Once these guys can access a broad market, they'll have the customer base and data to do great things, whether its in advertising or whatever other business model they stumble upon. One thing is certain: the opportunity in the mobile device market is only just being realized, there's still a whole lot more to discover.