I build a lot of stuff with Incanter[1], clj-ml[2] and Quil[3] for building visualisations. None of this is as joined up or as thorough as the equivalent R (or probably Python) bits. Clojure open source libraries are also incredibly prone to being abandoned. Wouldn't trade the language in for anything though, and I've never seen any R code that I would want to maintain myself.
[1]: http://incanter.org/
[2]: https://github.com/joshuaeckroth/clj-ml
[3]: http://quil.info/