Lately I saw that google is more interested in the site overall position than in the particularly content. For example, let’s take a search term very niche, like “djksalkjdfalkdjfalkdjf”, where there are not too many competitors. Or no competitors at all. 🙂
Before, if you had a page more or less optimized for this search term, even if your site is PR0 or PR1, your page would appear in search results. Now, things are changing. Site with no or less authority, even have the content right, are not shown as before.