Sorry, I'm out of touch. I visited CJCLR a long time ago (maybe a year or two) and had the impression it's a work in progress and a lot of basic things are missing. Is that no longer true, or was my initial impression invalid? Can I start learning Clojure with it and expect it to work more or less like “proper” Clojure?
There is a lot of Clojure code out there using Java interop. That said, a lot of "proper" Clojure runs across all three major runtimes (Java/CLR/JS) without any significant changes.
(while I'm here, let me also point out http://hylang.org in case you use Python - it's a nice gateway drug, if you'll pardon the pun)
I've never used ClojureCLR personally, but its wiki on github claims to track the main Clojure project within weeks, and the last commit was 2 days ago. There seems to exist a version 1.6.0.
That said, I bet the tooling isn't so nice to use as Leiningen, although there does exist a Visual Studio somewhere.