Very sad news, but inevitable, and perhaps not unexpected, given his health.
As one small tribute, I remembered something that Neil Gaiman said, in
this article about the writing of their joint work,
Good Omens. Gaiman had written a 5000-word draft; Pratchett read it and phoned Gaiman, offering to buy it, or to write it together.
"Write it together," I said, ... because that was the nearest I was ever going to get to Michaelangelo phoning to ask if I wanted to paint a ceiling with him.
