According to news from Photoproce.ca and Sony Alpha Rumors , RX1 compact cameras have full-frame CMOS sensor 35mm, or the same sensor with the A99 DSLR camera. As is known, of course, full-frame sensor will produce better images, and full-frame sensor is generally used on professional grade DSLR cameras.
From the leaked images that look, RX1 camera using a 35mm f/2.0 Carl Zeiss lens, pop-up flash, hot shoe and dial menu like on a DSLR. The camera is also rumored to be sold for about $ 2,799.