Those numbers you mention are not in the article, so where do they come from? Just looking at the annual report from 2008 (the first year they actually changed from production shipments to shipments to retail) I can't seem to find Sony mentioning an LTD for shipments to retail for PS2. So if you do have a source I'm curious about it.
Well, the numbers in the article are unit sales and are till June 08. They were posted here a few months ago btw. Those 136.32 is just from adding the two quarters. The 138.15 production shipment figure is from someone on GAF. Those are legit numbers.