Here is the brief spec.
Pre-Photokina 2010: Fujifilm has announced the X100, a large-sensor compact camera aimed at professional and enthusiast photographers. Based around a 12Mp APS-C CMOS sensor,
and here is a a bit from an interview picked from sonyalpharumors.com
“Question: It has been said that the sensor used is similar to that seen in some Nikon SLR cameras, and therefore manufactured by Sony. Can this information be confirmed?
Answer: The sensor of the FinePixX100 is customized to match its lens. We should point out that the most important thing is not who produces the technology but the technology in itself, and in this sense Fujifilm optimizes its technologies depending on the photographic result being pursued at any given time.”
So not a confirmation, but not a denial either. It looks as if the competitors are gradually one by one moving towards Sony sensors. I guess Sony need some new customers to compensate for the Nikon business they have lost such as the D3100. I now some people are "drooling" over this camera but it is most definitely not for me. Can't se the point with just one focal length lens.