Average data use is a meaningless statistic, and I'm sick of seeing people trot out those numbers to justify tiered pricing plans that punish people who use their smartphones for their intended purpose. I think the point of the article, as stated in the title, is that smartphones are here to stay and their usage is only going to grow. A few years ago, few people were interested in browsing the web over an EDGE connection. Now there are zillions of ways to be connected and entertained. Even non-geeks. Wireless carriers should facilitate this.
When AT&T dropped their unlimited data plan and introduced tiered pricing, it dropped prices for the light users and added modest costs to heavy users. There's nothing wrong with that, but please let's not imply that using less than 150MB per month is "average," or "normal," or in any other way desirable. If every iPhone user in my region were on Waze, our traffic would be vastly improved. And if they were listening to Pandora or Last.fm they'd all be happier.
At least that's where the vast majority of my 2.1GB per month of iPhone data is going. I can't say for sure, because all I get is the metered bill. It would be neat to see it broken down by traffic type.