Bing added instant translation as a smart answer or instant answer to their search. For example, if you search for how do you say search in spanish you get the answer "búsqueda."
Google also has some form of translation OneBox results, but they are not as discoverable as Bing. That means, you can't just type, how do you say something, or translate X for me.
Even more importantly, Webmasters approve of how this instant translation works in Bing. Not only is the translation pretty good, the way the translation shows up in the search results are "neat."
Forum discussion at WebmasterWorld.