Impressive indeed. Would you happen to know if Facebook is able to translate without using English as an intermediate language? For example, from Dutch directly to French, without needing to go from Dutch to English to French.
From what I recall reading, Google has people researching this internal language to see if they can discover any new interesting things about human thought.
https://techcrunch.com/2016/11/22/googles-ai-translation-too...
My impression of the pure DL approaches is that the preferred way to go about it is to map from each available language example, via a common latent representation, to every other available language example. The common currency is not English but a vector space representing something much more akin to the meaning underlying the statements.
English -> French French -> English English -> German French -> German