Identity has been a consistent theme of his movies (Inception, Memento, and the batman movies). So has nobility, truth, and adventure. Two of my favorite lines in Interstellar occur on earth, one about how we used to look up at the stars, and now just look at the dirt - not even ground, dirt, perfectly encapsulates postmodern, typically liberal, narcissism. The other in the confrontation between Cooper and his daughter's teachers. He also dwells on the nature of the abstract. Where Terry Pratchett, in Hogfather, once had Death remark that we cannot sift the universe so fine as to find one atom of Justice, they nevertheless exist. Despite the common misunderstanding as new-age pseudo intellectualism, Interstellar also anchors itself in the existence of love - that we cannot measure it, but we can show it exists by its effects - and how Coop knew his daughter would keep the watch because she loved him, and knew he loved her.
So I saw this trailer, and I damn well intend to see this movie.