I just updated the status on ClojureCLR from 'alpha' to 'beta'. This is not an attempt to improve the code via wishful thinking, but an update to the README to bring it in accord with the current state of the code.
The project is under active development. It is usable. Only beta because of some things that still need work: a few missing things in CLR interop (assembly-qualified names for types, handling generic types); a need for an installer for casual users (as opposed to the current install process more suitable for the hardy); and some more tuning for performance. The wiki on the github site (http://github.com/richhickey/clojure-clr) is the best place to get a sense of what remains to be done.
What it needs most at the moment is people using it.