Jumpman, I have to strongly disagree.
If Sony added 2 more controller ports, they would also have to add the m/c slots to go with them. This would upset the design and increase the cost.
They are already taking a loss on hardware. Alot of people, including the media were bit*ing about the $299 price tag. With the extra ports and m/c slots either Sony would have to take an even bigger loss per unit, or the price would have been jacked up to $330-$350.
It was a sound financial, business decision, and also had statistical backing due to the lack of 4 player support in both game titles and users.
....And besides, Sony doesn\'t even have a multitap available yet, do they?? It\'s the third party manufacturers like Pelican, and Interact that are making money off of Sony\'s (right) decision.