I wouldn't call it backlit, but basically it would be to flip the current sensor around and expose the back of it rather than the "front". Here's their press release from June: http://www.sony.net/SonyInfo/News/Press ... index.html If you get past the technical details, look at the diagrams with the angle of light, etc. which has been a huge problem for digital and light fall off. A sensor like that will make the consumer lenses shine and the professional lenses even better.
interesting read... it is stunning how much detail and tech goes into this stuff then they take it and completely flip it backward. those sample shots were filthy...