I'm excited for self-driving cars and ML/AI tools that help professionals (e.g., drug discovery, treatment).
The Keras lead developer wrote a post called "The future of deep learning"[1]. The podcast Partially Derivative has a good summary of it[2].
On the implementation side, I'm looking forward to distribution. Computers are all around us, sitting by idly – how can we put them to use? How can we make them secure? We're starting to see integration of ML models into mobile systems (with Apple's .mlmodel and ARKit).