I have just announced new v3.14159 which supports Bing Translator along with Google Translate. After Dec 1 it will seamlessly migrate to Bing Translator. You just need to get a Bing Translator API key from http://www.bing.com/developers/createapp.aspx
and insert it into config.php file.
If you turn on the USE_BING_TRANSLATOR option now, it will use Bing from now, otherwise it will start using Bing after Dec 1.