And unfortunately, it is not good news. Terry Pratchett has early onset Alzheimer's.
For those who are not familiar with Terry Pratchett, he is the author of The Wee Free Men and tons of other wonderful books for both kids and adults. We discovered him last spring and he quickly became one of the boys and my favorite authors. We have read all the Tiffany Aching books and I have been making my way through the adult Discworld books and thoroughly enjoying them.
While this is indeed sad news, it sounds like he is handling it with characteristic wit and perspective. As he put it:
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.
Terry Pratchett was one of the main draws for us when we went to the National Book Festival this past fall and he was incredibly entertaining to hear in person. You can see a webcast of his talk which was wonderful.
For more information on his books, you can check out his website.