Miscrosoft is paying Nortel, the Canandian manufacturer, $7.5 million to by 666,624 addresses. The sale will be finalized in April 26, 2011. The transaction puts a value on each address of $11.25.
There are currently only 4 billion unique IP4 addresses remaining. This is why it is valuable since the pool of this generation of addresses are close to running flat. Several giant companies are spending millions just to get a few more allocations.
The exact reason Microsoft has in mind for buying all the IP addresses are unknown. However, many companies are eager to run away from the cost of changing their networking systems over to IPv6 compatible equipment.
The deal is not yet approved by the court and anyone who is against it should file their comments before 4 April.