I'm not sure whether his illness was well known to those within the legal academy, but it came as news to me, so I confess I'm slightly shocked by news of his death. Others, of course, are much better positioned to give thoughts about his life and career, and no doubt will, here and elsewhere. I'll share just one brief remembrance. I was the founding co-editor of the Harvard Law Review Forum, and for our very first issue, I solicited a response from Professor Dworkin to Fred Schauer's (Re)Taking Hart. These were the days when online supplements to law reviews were new, and we didn't really know how scholars would view these opportunities. When he readily agreed to provide a response, I recall emailing the news around Gannett, to much rejoicing. This was an especially meaningful "get" for me, as in addition to his work in legal philosophy, I had read and appreciated Life's Dominion as an undergraduate studying bioethics. I was terribly nervous about interacting with him, but he was incredibly kind and gracious and unassuming throughout the process.
Professor Dworkin leaves behind his wife, two children, and two grandchildren. They and his friends and colleagues are in my thoughts.
Update: Brian Leiter is aggregating memorial notices here.