Google has finally written a blog post specifically about PageRank and how Webmasters and SEOs should probably focus on other things.
The blog post is named Beyond PageRank: Graduating to actionable metrics, written by Susan Moskwa, one of the fearless Googlers involved with webmaster communication.
She said, "PageRank is no longer—if it ever was—the be-all and end-all of ranking." She then goes on to explain:
If you look at Google's Technology Overview, you'll notice that it calls out relevance as one of the top ingredients in our search results. So why hasn't as much ink been spilled over relevance as has been over PageRank? I believe it’s because PageRank comes in a number, and relevance doesn't. Both relevance and PageRank include a lot of complex factors - context, searcher intent, popularity, reliability - but it's easy to graph your PageRank over time and present it to your CEO in five minutes; not so with relevance. I believe the succinctness of PageRank is why it's become such a go-to metric for webmasters over the years; but just because something is easy to track doesn’t mean it accurately represents what’s going on on your website.
Susan instead recommends you look at the following metrics that are "actionable" such as conversion rate, counce rate and clickthrough rate (CTR).
This is not the first time Google has downplayed PageRank. They downplayed it in the recent toolbar upgrade and we know that Google's Matt Cutts has always wanted PageRank removed from the toolbar. Adam, back then "mini-Matt" asked for feedback on the removal of PageRank from the toolbar. Plus we know, many SEOs want it gone from the toolbar. There were rumors in 2008 that Google was removing it and it 2009 they removed the data from Webmaster Tools.
Forum discussion at Google Webmaster Help.