Yup. He had a good run though--he was 90 years old or something. I'm sure when he awoke in his bed and saw the monolith come to take him away he wasn't all that upset (the monolith resides in his backyard garden after all--its only a short trip ;) )
I was sad when I saw this, though I must say 90 is a pretty good run. What we leave behind is very important and Arthur's books will still be being read for generations to come. One more great writer of our time joins the list of the greats from the past.
He will be greatly missed. His work, especially 2001, had a tremendous influence on my life. Now he can finally visit Stanley Kubrick. Two geniuses together again at last.