This story badly misreads Jobs' statement and is flat wrong.
Jobs wrote:
Unfortunately, my decision to have Phil deliver the Macworld keynote set off another flurry of rumors about my health, with some even publishing stories of me on my deathbed.
I've decided to share something very personal with the Apple community so that we can all relax and enjoy the show tomorrow.
It does
not say that Jobs had Schiller deliver the keynote due to his health, nor can that be reasonably inferred.
If you disagree, point out to me the exact language that says Jobs is not giving the keynote
because of his health.