According to Ray Franz the NWT translating committee was made up of Freddy Franz, Nathan Knorr, Albert Schoeder, and George Gangas (Crisis of Conscience, page 50). Since nobody on the NWT translating committee is alive today explains why there haven't been any 21st Century revisions to the JW Bible. The English language is a living language so words and meanings change. But a look at the NWT reveals that it was written in a form of English more common to the late 19th and early 20th Century. Therefore, a revised NWT is definitely needed, but probably won't happen.
Unless the GB has employed a medium to channel the NWT committee members from the great beyond, it's doubtful that a revised NWT is in the works.