It depends on who you ask. Different groups will give you different answers.
There’s no firm deadline because no one has the authority to mandate a change, and a full worldwide change over will cost billions.
Well there are a finite number of IPv4 addresses available for distribution. They are being allocated via the 5 RIRs to ISP’s as they are needed. Sometimes needs are higher and sometimes lower so the addresses are allocated faster or slower and the central pool usage
rate speeds up and slows down. If everyone in your office takes some jelly beans out of a big
jar when they want some try to calculate when the big jar will be empty. Not so easy eh.
The latest forecasts are that the IANA central pool will be depleted by July 2011 based on past usage rates.
IANA announced the depletion of IPV4 addresses on 01Feb2011 – with the allocation of 2 /8 subnets to Asia, teh remaining 5 /8 will divided evenly across the other regions:
” The Internet Assigned Numbers Authority assigned two of the remaining blocks of IPv4 addresses – each containing 16.7 million addresses – to the Asia Pacific Network Information Centre (APNIC) on Tuesday, as predicted.
IPv6 / Serious NAT’ing anyone?