In his keynote at JVM Languages Summit 2009, Rich Hickey advocated for the reexamination of basic principles like state, identity, value, time, types, genericity, complexity, as they are used by OOP today, to be able to create the new constructs and languages to deal with the massive parallelism and concurrency of the future.
Clojure After The Honeymoon is a case study from an investment bank, describing their experiences with Clojure after using it for a relatively long time.
Expert to Expert: Rich Hickey and Brian Beckman - Inside Clojure - Astrophysicist and Software Architect Brian Beckman interviews Rich Hickey to dig into the details of this very interesting language. If you don't know much about Clojure and the general problems it aims to solve, well, watch and listen carefully to this great conversation with plenty of whiteboarding and outstanding questions.
Evident Code at Scale - Stuart Halloway's presentation on scaling codebases, abstractions, "evident code", and how it all works in Clojure.
Programming With Values in Clojure - Alan Dipert discusses the benefits of functional programming in Clojure, suggesting using pure functions to process values and sometimes explicit procedures for needed side effects.
Why Prismatic Goes Faster with Clojure - Bradford Cross recommends creating custom libraries containing composable abstractions instead of monolithic frameworks, exemplifying with Flop, Store, Graph, and Newsfeeds, all written in Clojure.
What Sucks About Clojure And Why You'll Love it Anyway - Chas Emerick makes a critique of Clojure outlining its weak points related to namespaces, declare, dynamic scope, STM, JVM and others. Really hits some of the pain points for those of us who have been using Clojure for a while.
Simple Made Easy. This is about simplicity in software design, and is not specific to Clojure, though Clojure libraries and apps tend to often have the qualities outlined here.
The Value of Values - Another serving of Hickey philosophy. "Rich Hickey compares value-oriented programming with place-oriented programming concluding that the time of imperative languages has passed and it is the time of functional programming."
Clojure Programming is a newish tutorial book from O'Reilly. Currently the recommended first book.