I think that the post-colonial struggle for identity is what Saleem endures throughout the novel.  In this light, there is much in way of post-colonialism in the work.  Saleem is an interesting post-colonial character in that he is born at the precise moment when post-colonialism in India emerges.  Yet, his narrative is traced back to a time when colonialism is in full force.  This means that post-colonialism has a very odd relationship with colonialism.  On one hand, it seeks to be independent of it.  While on the other side of the coin and almost simultaneously, it cannot help but be linked to it.  In this regard, there is a very strange dynamic at hand with identity in the post-colonial world.  This is where Saleem is in the novel and what the reader understands as a result of this dynamic.  Post-colonialism expresses its search for identity through a complex set of conditions where uncertainty is present and a struggle to find some level of firm grounding is evident.  This is where Saleem, and most of India on the stroke of Independence and Partition, lies.  In the end, the only constant is that there is a struggle to establish identity.  This seems to be the sole bulwark that is taken from both Saleem's and India's struggle in the course of Rushdie's work.