I wrote a simple wrapper that is on github for calling the new API. The old API will not work starting in August 2012 so it was time to update. The README file on github has a simple example for using the JAR created by this project in a Clojure project (a pre-built JAR is also included in the github repository).
The wrapper is simple, but will save you a few minutes writing one yourself if you need to use Bing Web Search in Java, Clojure, JRuby, etc.
You get 100 free searches/day with the new API and there is a charge if you need more API calls per day.