The research proposal for my SoP is complete, but most schools want you to mention specifically why you are applying to their program. I'd be interested in hearing the kinds of things others have included--professors you're interested in, merits of the program, location? I could see doing it a number of different ways, and I'm curious to see what others are doing.
If it matters, I'm applying to English PhD programs--Stanford, Harvard, Yale, UVA, U Penn, UC Berkeley, Brown, U Chicago, Princeton.