There was nothing unexpected about the Internet running out of IPv4 addresses, except for how quickly the last few address blocks have been used up. As Rod Beckstrom, Internet Corporation For Assigned Names and Numbers (ICANN)'s President and CEO said in the announcement "This is truly a major turning point in the on-going development of the Internet. Nobody was caught off guard by this, the Internet technical community has been planning for IPv4 depletion for quite some time. But it means the adoption of IPv6 is now of paramount importance, since it will allow the Internet to continue its amazing growth and foster the global innovation we've all come to expect."
What does that mean for you? Well, in the short run, nothing if you're an ordinary user. If you're a CIO, network engineer or administrator, you've got to start getting switch to over to IPv6. IPv6, with its 128-bit addresses, won't be running out of addresses any time this century.
IPv4 is another matter though. The Asia-Pacific RIR, (APNIC) will be the first to run out. I expect APNIC to give up its last free address in the early summer. RIPE, which handles Europe, the Middle East and the former Soviet Union countries, will go next by year's end, and the American Registry for Internet Numbers (ARIN) will run out in early 2012.
If your business isn't ready for IPv6, and darn few are, there are some transitional technologies such as dual stack, dual-IP stacks, and Dual Stack Application Level Gateways that will let you use IPv4 and IPv6 at the same time.
If all that's Greek to you, talk to your networking vendor or your ISP. You're going to need their help to switch over IPv6 anyway. Many of them, such as Allied Telesis, Mu Dynamics, and Hurricane Electric have IPv4/IPv6 transition products and services ready to go.
As Alain Durand, director of software engineering for Juniper Networks told me, "The expected announcement from the Internet Assigned Numbers Authority [IANA] that the remaining large IPv4 address blocks have now been assigned has long been forecast and should be kept in perspective as global Internet growth will continue without interruption for a long time to come. Juniper Networks has been assisting its service provider and enterprise customers with a continuum of IPv4 exhaustion solutions, IPv6-enabled products and IPv4/IPv6 coexistence strategies for many years. There will be no disruption of service for the vast majority of Internet users, both wireless and wireline."
So long, that is, as you upgrade your network infrastructure for the brave new world of IPv6. If you don't, well don't be shocked if in a year or two, you won't be able to get Internet addresses for your new office or your VoIP (Voice over Internet Protocol) programs won't connect.