Exactly how the 3DS’s 3D technology will work is unknown at the moment, but many are looking towards Sharp’s 3D touch screen. Recently they showed it off to some press and they got to try it out a bit.
You can’t really use cameras to record 3D content, so everything is blurry as expected. But, it does explain some of the technology behind the screen.
Again, whether or not Nintendo will be using this technology is unknown at the moment.