Sad news. I agree with so many of the sentiments already expressed. His art had more imagination than all of modern Hollywood combined. I know he's best known for Star Wars & other film concept art, but he did SO much more. I really love his aviation art.
But I must confess that my absolute favorite pieces he did are Star Wars related. While I love all of it, I can never get enough of the works he did just showing glimpses of everyday life on a foreign world. They REALLY get my imagination going. I really need to get that book of his that was put out s few years ago...