Ordinary users don't have to worry about switching from the old-style IPv4 Internet to IPv6... yet. Businesses are another matter. Europe, the Middle East and some of Central Asia ran out IPv4 addresses in 2012. The rest of Asia used up the last of its IPv4 addresses in 2011. The United States, Canada and the most of the Caribbean Islands? We're due to use up the last of our American Registry for Internet Numbers (ARIN) assigned addresses on January 6, 2015. Lucky us.

Fortunately, we are slowly, ever so slowly, moving to IPv6. In no small part that's because of the growth of 4G phones and tablets
Read more at: IPv6 gathering momentum | ZDNet