I don't care at all about PR, it is easy to get PR. The only time I'd really care about PR is when I have got a PR6+ website. Live by the PR you will soon dies by the PR.
I think it only matters if you are running a blog and depending on income from programs like PayPerPost and TLA type ads. My blog hasn't existed during the last PR update, so I still have a PR0. This means that my moniterization is quite low.
If PR means you have an authority site then it is possible for your high PR site to scrape the files of another lower PR site and remove the original from the SERPs. We have an experiment actually attempting this now. http://www.omg-1.com/experiment.html and our Duplicate Content Knock Out Challenge
Here is another reason that PR is important -- new sites often won't be accepted in directories until they have PR and that is usually PR 3.