According to Mission Repair, Apple's iPad has a space for an iSight webcam/camera inside the device. Based on parts seemingly obtained through unofficial channels, the frame appears to have a very similar area to the MacBook's existing iSight webcam enclosure.
If true, this is almost the exact same situation that occurred with the iPod touch G3, which was widely rumored to be getting a camera, ended up being introduced without one, and was torn-down after release to show the area where a camera was ready to go.
In that case, it was said Apple wasn't pleased with the quality of the cameras they'd received, and so pulled them at the last minute. Could they have received a second bum batch for the iPad? Could they have tested out the awkward camera angle enforced by holding an iPad flat on the lap and decided no one needed to see the undersides of their chine? Seriously, people, we're running out of ideas as to why there aren't any cameras on these devices. Let us know what you think!
UPDATED: Did the demo iPad shown off by Steve Jobs have that missing iSight camera? Florian sent us a link to screen shots