If we all have devices in future that can instantly translate from one language to another, there would be no need for people to learn different languages for business, travel and communication.
It would mean that any book in any language could be read by anyone in the world in their own language. TV and movies could have instant translations and all websites would be accessible to everyone, no matter what their native language might be.
FOr this to work, the translation software of the future will have to be much better than translation tools available now. I think it would have many advantages, but it would be a shame if people no longer bothered to learn to speak a second or third language.