Via the fan's fan Avedon, the bad news that Terry Pratchett* has a rare form of early Alzheimer's disease. Via (the Beeb (Paul Kidby)):

We are taking it fairly philosophically down here and possibly with a mild optimism. For now work is continuing on the completion of Nation and the basic notes are already being laid down for Unseen Academicals. All other things being equal, I
expect to meet most current and, as far as possible, future commitments but will discuss things with the various organisers. Frankly, I would prefer it if people kept things cheerful, because I think there's time for at least a few more books yet )

Terry Pratchett

And the PS:

PS I would just like to draw attention to everyone reading the above that this should
be interpreted as 'I am not dead'. I will, of course, be dead at some future point, as
will everybody else. For me, this maybe further off than you think - it's too soon to tell.
I know it's a very human thing to say "Is there anything I can do", but in this case I
would only entertain offers from very high-end experts in brain chemistry.

Classy.

NOTE * You don't know who Terry Pratchett is? Avedon thinks the star is the Patrician, but I think Sam Vimes is Archie Goodwin to the Patrician's Nero Wolf.