Links to various obituaries can be found on Brian Leiter's Leiter Reports. Several colleagues have noted special memories of Dworkin and this seems a good time to do the same.
I never met Ronald Dworkin, but we wrote to each other a few times when I was a graduate student at the University of Sheffield. My Ph.D. topic was Hegel's political and legal philosophy. The thesis had an introduction with four chapters - each "self-standing" and leading to several publications in the Bulletin of the Hegel Society of Great Britain (on Hegel and punishment), History of Political Thought (on Hegel and monarchy), Review of International Studies (on Hegel and international relations), and two papers on Hegel's legal theory published in Georgia State University Law Review and Res Publica. My Ph.D. thesis was later expanded and published as Hegel's Political Philosophy: A Systematic Reading of Philosophy of Right in 2007 with the paperback edition appearing in 2009 and a new second edition out this year.
My largest chapter concerned a critical comparison of Hegel and Dworkin regarding their legal theories, later published as "Between Natural Law and Legal Positivism: Dworkin and Hegel on Legal Theory" (and my position has changed somewhat since then - see my "Natural Law Internalism" published in Hegel's Philosophy of Right (Blackwell, 2012)). I argued that one reason why many scholars have had some difficulty in classifying the legal theories of both Dworkin and Hegel is because each offers a novel perspective -- and, interestingly (at least for me), this perspective - of Natural Law Internalism - is broadly similar. One consequence is that each is subject to similar problems that further distinguish their views from others.
I wrote on a few occasions to Professor Dworkin by email to say that I was deeply engaged with his work and was curious about what he thought of my draft chapter. It didn't take long for him to reply - and by a letter in the post each time - always gracious for my messages and full of encouragement. On one occasion he noted that he had long been "intrigued" by the possible connections between Hegel's views and his own.
I remember the great feeling I had of receiving such comments on my doctoral work by such a major figure despite our never having met. While I always sent my thanks, I never had the opportunity to thank him personally. But I like to believe I might continue the generous spirit of support to others from my much lower position that Dworkin (and many others) showed me.
While I've remained critical of many elements in his work, it is true that I probably would not have become interested in legal philosophy when I did if it wasn't for Dworkin. He will be missed -- and reminds me to complete at long last a substantial critique on the role of principles in his work I've left on the philosophical work bench for too long as a small tribute (of sorts).