I have heard rumors for months that Jim Benson had had a stroke. Apparently, it was a different problem, though whether a better or worse one is hard to say. In any event, he lost the battle, as will we all, ultimately.
I may have further thoughts later (de mortuis nil nisi bonum, and all that), but for now, my condolences to Susan and his children.
[Saturday morning update]
Clark Lindsey has several other links on the story.
Whatever else his legacy will be, he showed that a savvy businessman can start a successful commercial publicly traded space company from scratch (though admittedly, much of the growth was via acquisition).
Requiescat in pace. He was a worthy competitor.