According to unreliable sources (CR1) from Canonrumors the mirrorless “Canon will use an APS-H (1.3x crop) sensor.”
My opinion? FAKE!
Leicarumors received a new hint “We will see a full frame Leica EVIL on Photokina 2010. It will look like the Leicaflex 18X24 prototype. Of course without mirror or the film lever and so on. It will be a VERY small system camera, but there will be a big battery grip you can use“