Fujifilm has released a statement which says that they are developing a modified sensor for their X10 and X-S1 cameras, which should (hopefully) address the
white orb problem once and for all. It sounds like owners of the X10/X-S1 who have been affected by this issue will be able to send their camera in for a sensor replacement or camera exchange. The new sensor should be available in May.
Why do I get the feeling that I'll be reviewing the X10 Mark II in a few months?
(Thanks, DP Review)