I don't follow your logic... Without those different languages, you wouldn't have anything to translate in the first place. If anything, this type of technology promotes independent and different languages, as it makes it so much easier to communicate with others regardless of your native tongue.
Also, bravo to Microsoft; I'll remove my jaw from the floor after I watch your video a second time.
different languages emerged because of physical separation. As barriers have been reduced because of technology (both physical and communication barriers) there really aren't "borders" anymore. I can call someone in China right now if I wanted to, something impossible to do even just 100 years ago.
So if we can all talk to each other across the world in real time, and we can all understand each other because of this technology, what exactly is the point of different languages anymore?
As a polyglot (English, several dialects of Chinese, Spanish, German, Russian), languages are still one of the most important tenets of culture and individualism.
Trying to understand or think like an American is a completely different experience from trying to think like a Chinese which, respectively, is completely different from thinking like a German. These modes of thinking not only make each culture/country/peoples unique, it actually facilitates various strengths.
Primarily, the Chinese language actually allows humans to remember and store more information in short term memory when compared to more Western/romantic languages. Most humans can store 7 (+- 2) bits of information (bits being defined as one contextual idea: 25 + 23 are 3 bits, Picasso's Mona Lisa is 1 bit).
The Chinese language actually facilitates math/short-term memory because many things are spoken/read/written as one contextual idea. When remembering a large number (602-112-5097 for example), English speakers tend to remember this number as:
Area code = 1 contextual bits
Each individual number = 7 contextual bits
This happens because the English language separates non-related digits into individual ideas.
In Chinese however, masses of digits are written and spoken as one long contextual idea. Similarly, in memory, these long numbers are more easily stored as one contextual bit and take up "less" space.
Conversely, English (and to some degree romantic languages) happen to have lots of descriptors (what we call adjectives and adverbs). This, respectively, is one of the reasons why English speakers tend to be more creative with how they express themselves.
Does this mean that we'll eventually tend towards an universal language that implements all the good points of current languages? Perhaps.
Personally, I enjoy the uniqueness of each language by itself.
> "So if we can all talk to each other across the world in real time, and we can all understand each other because of this technology, what exactly is the point of different languages anymore?"
A bunch of things. First and foremost: cultural representation. There are many things that are simple words in Chinese that have no English equivalent. The values and traditions of a culture are subtly communicated via its language, and even if we can instantaneously translate the literal meaning of what is being spoken, subtext will be lost.
This is why at a high level (beyond "where is the restroom") translation is a highly involved field.
Secondly is the usability of this system. Even if it is 100% accurate and immediate you'll just end up with the UN problem: communication becomes asynchronous because you need to wait for the translator. You'd say one thing, the other person would listen to your translator. He'll say something back, and you get to listen to his translator. It's a hell of a lot better than nothing, but there is still a tremendous advantage to being able to converse in real-time.
Following a little of what nathannecro said, I think that the real consequence of this technology is that it makes language more useful, more important as a conceptual tool than ever before. Studying language in within an environmental model is an amazing tool for understanding how languages were formed, but if the previous barriers for communication are shattered then it seems to me language itself won't be at such a loss, rather the linguists of the future will have to expand their models to see what happened once everyone got sms/twitter/skype with PerfectTranslator or whatever it becomes. Language allows you to do more than just communicate with others, it allows you to conceptualize. Cue obvious comparisons to programming, where the product is often bound to the process of its creation. We identify the paradigms and then work them to our advantage. If we continue to promote language learning and develop newer, better systems for facilitating that task I think it would be greatly beneficial, basically as long as we humans still exist and aren't delegating everything beyond our beating hearts to a digital circuit.