A number of folks at Dpreview are now reporting that they have had the sensor changed in there X10's. For the most part this seems to be a positive move with the blooming issue being resolved. I have had the chance to observe a number of shots from these folk and by and large things appear to have been solved. I'm not entirely convinced that the new sensor is as crisp as the old one, but for now am willing to put this done to the differences in image display depending upon provider.
The XS1 apparently isn't considered for a overall sensor replacement, but it seems if you can prove the case (ie: send some images with the camera) they will consider the sensor exchange. It would be wise to check with your local Fuji dealer or the sales staff at Fuji headquarters for each country to check if this service is being offered for your locality. It also at this point appears that the lens droop issue isn't even being acknowledged by Fuji, even though many owners have reported this phenomenon to varying degrees.
Kim Letkemen is currently reviewing the XS1, and has reported that the lens droop appears to compromise the acuity of the lens.
You can see his full report here. Kim is a RAW shooter by preference , so if its RAW you prefer this article will definitively be of interest.