Finally, we're just a millimeter away from getting to my point:
Would you not prefer to have an even clearer FaceTime with, say, 3-megapixel camera versus 0.1-megapixel "chessboard"?
No. I would not. For many reasons. Since you don't seem to be a photography expert in this case I'll clarify.
1. Since a 3 megapixel image is resized to do video chat. As previously stated 720p video is less than 1 megapixel. 1280x720 = 921600 pixels. Even 1080p is ~2 million pixels.
1a. Any Larger image would be resized to fit into these stream sizes. Resizing images is processor and time consuming, and will generate artifacts.
1b. Streaming 720p video let alone 1080p is straining internet connections, and actually even wireless networks themselves. Which I assure you the ipad 2 is going to be a wireless device, and not likely to have a gigabit ethernet port to plug in. So until we're much farther along in internet infrastructure, there isn't a use for more megapixels you do not display
1c. Given that facetime uses wireless streaming, the video stream itself undergoes compression which is lossy, and you would lose alot of the detail anyways.
2. Megapixels are a myth perpetuated to market to people who don't understand the very basics of photography. Old film cameras used 35mm film, hopefully most of you remember how big each negative was. That used the entire surface to gather light. And in photography, the amount of light you can use is fundamental. Remember the size of a negative for 35mm, now did you know that the light sensor inside a decent point and shoot camera is as big as the word "like" in this post. And they cram 14 megapixels into that. Each pixel gathers so little light and is so close to the others that it generates alot of noise. The sensors for cell phones, webcams and such are even smaller, probably about the size of the letter "o". Cramming more megapixels into that does not get you sharper pictures, just more noise. If you take a look even many of the professional cameras don't sport that many megapixels, and the sensor size is much bigger, say a large postage stamp. So each pixel in one of those cameras is much larger than a pixel in the cell phone, can gather more light and produce much better images. Even the prosumer point and shoots, ie Canon S95, G12, Panasonic LX-5 etc are only 10 megapixels but boast larger sensor sizes than ordinary point and shoots. And I will say the resulting pictures are much better, due to better optics and much larger light gathering capacity per pixel. In a device like an ipad, where you want it thin, and more than likely to video chat, a lower resolution sensor that fits the stream sizes will generate a better picture, especially in varying degrees of lighting.
3. Anyone who would shoot a video with an ipad on any consistent basis probably should have their head checked lol. You're far better off with almost anything else that's a real camera.
Wiki article on sensor sizes for more info
