There's another reason to read their papers, which I describe in "How to get your Professors’ Attention — along with Coaching or Mentoring" (http://jseliger.com/2010/10/02/how-to-get-your-professors%E2...): you want to signal to your professors that you're worth investing in. Most people aren't, and one way to distinguish yourself is to read their work, since the majority of students—even those who say they will—won't.