well i'm no adcom or anything, but if i was, i'd be looking specifically for what makes you different from last year. if they didn't accept you last year with your application, what has changed that they might accept you this year?
if you don't tell them what makes you a better applicant this year in your essays, how do you expect them to know.
plus i think the more dangerous part is that they could look at your using the same essays as a sign of laziness and lack of effort.
i think if you can think of other things to write about, you should.
dave