I came across a pretty interesting site today that shows how important links are to your site (just in case you think that they aren't). I'm not going to reveal the site here because it is not one of my own or one of my clients, so you'll just have to trust me that all of this is true. This person came to be concerned that none of their pages were showing up in Google.
The site in question is a PR 5 site that is not indexed in Google. Not a single page is indexed, and it never will be until they fix a 500 server error that is in the header of the site. The really strange thing is that the site displays just fine, but the server is returning a 500 error for every page load. Google will not index pages that return a 500 error.
I just think that it is interesting that even though Google can't index the site, and therefore knows nothing about it's content, it will still award it a nice PR because of all of the backlinks it gets (lots of edu backlinks). This is just a good example of how PR flows to a site, and really has nothing to do with the content on the site. So if you want high PR, just make sure you are focusing your effort on links.