EPhotozine has posted a comparison of the new Canon S100 and Fuji X10. It is odd because it runs counter to most of the other reviews that I have read. While their final conclusion is that the X10 is better, the images out of the Canon are noticeably better. The tests aren't the best since all of the Fuji's images were taken at ISO 400, while the Canon's were all taken at or below ISO 160. On a small sensor, ISO400 is pretty tough.
We are also comparing Canon's JPEG processing, which is excellent, to Fuji's, which is indeterminate. For example, the Olympus XZ-1 has, far and away, the best lens on the compact market. But from the JPEGs, you would never know that.
Based on other info, I still think it a definite that the X10 is better, but the Canon musters a good show.