I saw one yesterday as a friend did pick one up. It was really cool to look at directly. It's 3D in a way that the image on the screen does appear to have some depth to it.
However the second i looked at it from a different angel, the screen did give me a slight dizzy spell.
Actually it's being remastered according to numerous sources, as in mechanics touched up and textures/performance being scaled up to more current (but still portable) standards...that plus the 3D.I've heard only the 3D aspect makes Ocarina of Time that much better. Being my favourite game of all time that's what I'll be getting first once I do buy the 3DS.
I have used the device. It really isnt all that great. I dont see what the fuss is over. The 3D without glasses is decent, but you basically feel like your drunk and looking through a coke bottle at the screen.
The other people i work with who tried the demo all ranted and raved. But for me spending $250 on a device that really isnt that great is not worth it. I would rather put that money toward a high end video card than a device that i will play like 3 games on and have it collect dust.