They have also ruled out a 3D handheld of their own (at least one that doesn't require 3D glasses). With Sony pushing 3D so hard you would think this would have been something they would go for regardless of the precision.
http://www.gamesindustry.biz/articles/sony-slams-3ds-tech
Sony slams 3DS tech
Alec Meer
21/06/2010 @ 08:40
Sony is unconvinced that glasses-free 3D, as used in Nintedo's upcoming 3DS handheld, is suitable for gaming.
SCE Kaz Hirai offered his reaction to Nintendo's new portable to Sankei Biz, and while it was primarily a criticism of a rival firm's 3D technology, it shone some light on persistent rumours about a new model of PlayStation Portable.
"Based off internally conducted research, naked-eye 3D for portables does not have high precision," he said, "and at present there are limitations."
Hirai revealed that he had yet to see a 3DS first-hand, but told Sankei Biz that Sony would not be pursuing a similar technology for its own portables.
(More at the link)