prometheus - What was Weyland suffering from?

In Prometheus, it is shown in 2089, Dr. Shaw and Dr. Holloway discovered another cave-drawing of so-called engineers. In 2093, they reached LV-223. They have been asleep for two years (The geologist told the biologist I have been asleep two years) . That concludes both the doctors met Weyland in 2091. But when Weyland had told in the video And I am long dead in the ship, nobody became surprised.

So was Weyland expected to be died by that time? What happened to him? Was he suffering from some sort of disease? Or he was very old and that is why everybody thought he might have been died. It seemed that the crew knew that Weyland was going to die very soon. Holloway said Wow! Never talked to a ghost before, who met Weyland himself. I did not understand that part.