A very interesting source of thoughts is the work done by Bret Victor http://worrydream.com/ (take a look at Recent Output section).

Code the way we know it today will change. After all, human languages keep changing.

However, changes will happen in a very natural way, with selection of the best compromise between efforts and results. For instance, programming languages might not change that much while we might end up with more and more powerful frameworks to build software.

Nevertheless, next 50 years of evolution will be very very interesting to follow.