Sony's recently announced A7s boasts some pretty mind-boggling light sensitivity. Even though the camera hasn't reached the hands of the masses yet, Sony posted this low-light test to give you an idea of its ability to laugh at darkness.
The A7s has an IS0 range hitting 409,600 at the top, which is pretty remarkable. You can see in the video how even at ISO 1600, the scene is basically completely dark. Once the A7s is ramped up to its maximum IS0, you see a perfectly clear, abeit very noisy, scene. Wow! [YouTube]