When I used Skype Translator in December last year, it was breathtaking. I held a conversation with a native Spanish speaker in spite of not speaking a word of Spanish.
Since then, Skype Translator has added more languages—it now speaks Mandarin and Italian in addition to English and Spanish—and in instant messaging it handles many more, some fifty in total, including Klingon.
Until now, the preview has had only limited availability; interested parties had to sign up specially and could not get immediate access. That limitation ends today. The preview is now freely downloadable (Windows Store link) and available to anyone using Windows 8.1 or Windows 10 preview.
Wider availability and usage should enable Microsoft to further enhance the speech recognition and translation accuracy. Redmond hasn't yet built a babel fish, but the open preview is bringing that sci-fi future one step closer.