You can now find online the presentation slides that Rich Hickey used in his talk at the JVM Language Summit about the new concurrency features in  Clojure. In this presentation Hickey explores the important aspect of Time and how observers might view the same dataset at different timelines, and how this time disparity is a key issue in developing concurrent software. A good read indeed, although I hope the video gets posed online sometime soon (maybe at InfoQ?)

Are We There Yet? Rich Hickey's presentation slides