It seems Sony is beginning to phase out the PS2, at least right now. On January 2, it ceased shipping new models of the system to the island nation of Japan. Once the current stock on the island is bought, there won't be another shipment.
This story comes through Gamespot article by Eddie Makuch, which in turn heard about it through a Famitsu report (via Kotaku).
The PS2 launched in 2000, in Japan in March of that year, and has sold about 154 million units worldwide. Over 10,000 titles are also available for the system, and Sony has sold an excess of 1.5 billion PS2 games since its launch. To date, the PS2 is still the biggest-selling system in history, even more than its predecessor the PlayStation (which for the longest time held that distinction).
PS2 units will continue to be shipped to other countries, and no word has been dropped yet as to whether Sony will cease shipment to other countries. And though Sony has stopped the shipments, they will continue to produce titles and some accessories for the PS2 as they will throughout the rest of the world.