Christopher Nolan is my most respected filmmaker due to his crazy dedication and authenticity, but - for the record - he also knows what people likes, and have to admit that, he is not a big risk taker. He is very careful with the themes and genres. Also I can't believe he made such a superhero TRILOGY as batman, which broke box offices, and yet Marvel is still feeding us with its crappy junk replications.

I think Interstellar was the one, where he took the least risk he has ever done, and simply went for the everything, which is hip in filmmaking nowadays:

-Post-Apocalipse -Sci-Fi -Matthew McConaughey -Time's relativity (2nd time after Inception??) -Hans Zimmer etc. (smart kid, wormhole...)