How has the application review process for NSF graduate fellowships changed?
First off, as a single data point, I was awarded the GRFP this year with only three reference letters.


  Each application consists of the following components: a 2-page personal statement; a 2-page description of past research; a 2-page description of proposed future research


Currently, the GRFP requires a 2-page Graduate Research Plan Statement, and a 3-page Personal, Relevant Background and Future Goals Statement. This latter essay combines and shortens the previously required 2-page essays.

That's the only thing in JeffE's post that is obviously no longer true.