> This size is comparable to the worst compact DSLR's (the four-thirds system used by Olympus and Panasonic)
Are you sure? The article says the whole camera module is about 1cm in width and height. 4/3 sensors are 13x17mm.
Sensor sizes are very weird, 1/1.2" is not the diagonal: http://www.dpreview.com/learn/?/Glossary/Camera_System/senso...
Looking the table there, I would guess this sensor is about 10x7mm, which is huge for a compact camera and 4 times (not many) the area the iPhone 4S, but a quarter of a 4/3.
However, it's incredible they could fit the lens for such a sensor in a phone, and in fact you see in the video that it's already quite thick in the camera side.