IPV6

There's a good OECD report on IPv6, - "Only 16% of the total IPv4 address space remains unallocated in early 2008. The situation is critical for the future of the Internet economy because all new users connecting to the Internet, and all businesses that require IP addresses for their growth, will be affected by the change from the current status of ready availability of unallocated IPv4 addresses."

http://www.oecd.org/dataoecd/7/1/40605942.pdf