Updated Indianapolis, Indiana
You probably can't know but don't let that worry you. The key is to be prepared for changes. Make your studies basic and broad and look for ways to make experiences (either your own or those of other people, current or historical) apply to the situations around you. You want basic understanding of science, economics, psychology, and sociology and be able to communicate and explain clearly. You don't have to take courses in all these but don't reject learning about areas beyond your dominant interest. You'll be better able to adapt to things as they change if you can apply elements from various study areas to future changes.
Updated New York, New York
The key to being relevant is to keep learning, sharing what you know well and being open and applying yourself to every change/ challenge/ opportunity that comes your way. Continually identify areas in which you thrive/ are creative and keep pushing the envelope on what you can do by observing whats happening in the world. Ask yourself often- did I make a difference today? Your specific interests/ path may morph/ change through your life....but follow these basic principles...you will continue to think in new/ innovative ways which technology cannot replace easily.
You grow with your career. Keep learning the up and coming trends and technology. Keep the open mind and always willing to learn even if you are 50 years old. Even the latest technology still need people to monitor.