The author of Keras, Francois Chollet, posted today a very interesting article about the limitations of deep learning on its Keras blog : https://blog.keras.io/the-limitations-of-deep-learning.html
This will probably be included in his deep learning book. The part about extreme vs local generalization is inspiring.
Edit (2017/07/18) : Update on the url link. The old link now refers to The future of deep learning published today and also very interesting : https://blog.keras.io/index.html