Rich's writing, presentations, and example of overall conceptual discipline and maturity have helped me focus on the essentials in ways that I could not overstate. I'm glad (but not surprised) to see so much appreciation for him around here, even among non-Clojurists (like myself).
At the risk of fanboyism, I am constantly referencing his ideas* to my team, and I give them my blessing to watch any of his talks as soon as they come out.
* That is, the old but sometimes obscure ideas whose importance he's brought to his audience.