taking pictures?

Otherwise it can't read the Nintendo AR cards

Lol tbone...He got you.

It still can take and record 3d pictures. You will just need another 3ds or other 3d viewing device to see them. And also the ar cards use the cameras.

AR cards don't need 3D cam, it can "see" with 1 cam just fine.

I think nintendos ones do..  think the software to see the AR cards is setup so it uses both camera's.. Left camera picks up some points and the right camera picks up other points for calculating the depth or something like that

Shrugs. Maybe Nintendo has a sweet deal on the 3D camera component and/or get a more favorable price on the component the more they order (so including the camera in 2DS can mean cheaper camera prices for the 3DS models that actually have a use for it).