I think, like with the rest of Clojure, none of this is "revolutionary" in itself. Clojure doesn't try to be revolutionary, it's a bunch of existing ideas implemented together in a cohesive whole that can be used to build real complex systems (Rich Hickey said so himself).

Transducers are not new or revolutionary. The ideas have been around for a long time, I still remember using SERIES in Common Lisp to get more performance without creating intermediate data structures. You can probably decompose transducers into several ideas put together, and each one of those can be reproduced in another way in another language. What makes them nice in Clojure is, like the rest of Clojure, the fact that they form a cohesive whole with the rest of the language and the standard library.