well I would say that having high quality links is important,but the other factor is the amount of traffic a site recieves which I am sure is a major part of googles algo.
There is also the age of the site which I believe to be an important factor ,also the quality of the usefull information a site puts out.
Our Volks site has a PR 2 but heavy traffic so can beat any site with a PR5 or more .
well thats my theory.
A