With the third-generation iPad, Apple has resurrected the iSight name to refer to the 5-megapixel rear-facing camera, as opposed to the front-facing FaceTime camera also found on the device. As noted by Phil Schiller during the product's introduction:
On the back we have a camera, and when that camera gets of such quality and capability that you're proud to use it as your everyday camera for photographs, we call it an iSight camera. And the new iPad has a great iSight camera.As noted by @hashim_i, Apple has also retroactively applied the iSight name to the 8-megapixel camera found on the iPhone 4S, an understandable move considering its higher resolution and nearly identical optics compared to the new iPad.
In addition, Apple's iPhone 4 tech specs are now referring to that device's 5-megapixel rear camera as an iSight camera. The naming convention has not, however, extended to the 3-megapixel iPhone 3GS camera.