From the folks over at ARIN (American Registry for Internet Numbers):

“Effective today, because exhaustion of the ARIN IPv4 free pool has occurred for the first time, there is no longer a restriction on how often organizations may request transfers to specified recipients.

In the future, any IPv4 address space that ARIN receives from IANA, or recovers from revocations or returns from organizations, will be used to satisfy approved requests on the Waiting List for Unmet Requests. If we are able to fully satisfy all of the requests on the waiting list, any remaining IPv4 addresses would be placed into the ARIN free pool of IPv4 addresses to satisfy future requests.”

Onward and upward to IPv6! It’s worth noting that under IPv4 structure an estimate 2^32 IP addresses were viable, or about 4,294,967,296 sets of 4 octets. A little less than 4 billion IP addresses were actually available to be used, but damn, that’s still a lot of addressing.