I've played Arkham Asylum and Enslaved using this feature, and I think the effect is so-so. Not the true 3D you get in theaters like James Cameron's Avatar.
personally, I'm waiting for Sony's Stimuview [whatever] bundle to hit retail demos to see for myself.
Also: Crysis 2 3D sucks (it's fake 3D), GOW3 3D is just ok (half fake 3D), Arkham City is ok (low depth), Avatar is pretty good, de Blob 2 is good, 3D Infinity is ok, the rest are average.