The ending of the work is a fairly cynical view towards the nature of humanity in revolutions. Orwell makes clear that there is a difference between achieving political power and sustaining one's control of it. The hopeful and zealous protestations that bring about the former usually do not appear in the latter. Orwell understands that hope for political change does not always triumph over the baser instincts of humanity that seek control and power. The ending of the work in which the pigs have become the new humans is a reflection of what will emerge later in pop music with The Who: "Meet the new boss/ same as the old boss."
For Orwell, political revolutions present unlimited opportunity to change reality. However, someone is going to have lead the revolution and someone wil have to guide it afterwards. In these realities, Orwell sees a limited sense of hope, in that he feels there will be people who will resemble Napoleon, seeking to maximize power for themselves. In ths idea that there are individuals who use revolutionary claims in order to substantiate their own power grabs and consolidation of control, Orwell is able to make a statement about the nature of political change and how human nature might supersede it.. The ending in which humans and pigs are no different becomes a testament to this idea.