CNet on Dec 5, 2008:

Apple announced ... 300 million applications have been downloaded from a catalog that now tops 10,000 different apps.

Most of those applications are just an interface with the "infocloud". I wonder how difficult it would be move them to a different mobile platform. Despite all the hoopla, Microsoft and Google might not that far behind. The long-term dominance in the enterprise software space is at stake here. Any company that figures out a way to tap into mission-critical business applications will come out the strongest out of the current industry downturn.

As a side note: this would be a good example to consider in the class with regard to the 10x diagram. Specifically, students need to appreciate how Apple drives increase in user interaction with the iPhone/iPod ( the Time axis).