Some people say PR is not important at all . Thats completely false .. PR is crucial and getting backlinks from relevant sites is even more important. PR is a way to rate your site urself.
Getting backlinks is crucial to ranking well with google. Getting backlinks from authority sites is going to increase your PR. PR is the results of getting good backlinks. Getting PR from sites that have nothing to do with your site will only increase your PR, not your rankings. How PR is obtained is what is really important. A high PR will also allow you to get better backlinks as many other webmasters will be willing to do link exchanges.
to me it shows how google views the site...and since they are the biggest SE right now...to me that is important.