I am guessing that for a number of the deferred students, they are looking at part II of the application and wondering what they should write about in their essays. I am also guessing that most of you do not want a long post about how to write essays, so I will make this quick. First, do not rush the essays, as just like the application, you do not get a gold star for getting part II in first.
Second, I would suggest you look at my Suggestions for Writing Admissions Essays page, as it gives you some details about what we look for, and also what to avoid.
Third, here are links to posts from last year with real essays from students who applied (and were admitted) last Fall. These are extremely strong essays, so do not feel like your essays need to be this impressive. Just do your best, write what you think and feel, and do not write based on what you think I want to read.
Good luck, and Go Dawgs!