What are the 'hottest' future areas of Machine Learning and Data Science?
There is a brilliant answer by Yann LeCunn recently on a Quora session. 
What are some recent and potentially upcoming breakthroughs in deep learning? As he quotes, adversarial training proposed by Ian Goodfellow is one of the hottest area. Apart from that, I think Memory Networks, RNNs are widely used right now and can solve various problems up ahead.

Coming to what companies might do, I see a lot of text analytic companies. Considering the amount of consumer data we have now, there is a great need to be able to understand and analyze it. Computer Vision using ML or Deep learning is fast catching up. Using cameras for face detection, object tracking, fraud detection, tracking number plates is a huge field for companies to handle. 

Also, I think this might help you to prepare. To catch up with the overlooked developments, refer this which might give you an insight about what can develop in the future.