Cisco released a nice infographic called 'The Internet of Things'.
The interesting part is that there are more 'things' connected to the internet then there are people in the world. And we are not just talking about pc's, laptops, smartphones and tablets. There are a whole range of new developments and products that are connected to the internet. I think that this infographic nicely visualizes that the internet is not just a 'people' internet anymore. Not every device has a user behind it requesting information from the internet. It has become much more than that. In the comming years we will see much more of these new developments, now that wireless access (WiFi, 3G) are getting much wider acceptance due to lower costs and more covering.
For us, as users/developers/architects working with PI this opens up a whole new range of possibilities. Many of these devices need to interconnect, store and share information. In a lot of cases, this will be timeseries or asset data. It really makes me think what new possibilities and markets are out there for the PI system. With a lot of functionality and applications moving to the cloud, and now that the sharing of information becomes more and more important, I envision a whole new future of unexplored possibilities for us!
edit: I think Cisco might have exaggerated the statement that 'At the end of 2011 20 households will generate more traffic than the entire internet in 2008'. The facts really state otherwise, even if you compare the world wide internet traffic of 2011 to 1998 this statement still does not seem true. Wikipedia has some nice information about the history of Internet traffic here. Besides this, the infographic shows some nice insights.