I wrote last July about my small bit of code on github that wrapped the Microsoft Bing Search APIs. I recently extended this to also wrap the Translation APIs using the open source project microsoft-translator-java-api project on Google Code. I just provide a little wrapper for the microsoft-translator-java-api project and if you are working in Java you should just use their library directly.
Hopefully this will save you some time if you need to use the translation services. The free tier for the translation services is currently 2 million characters translated per month.