Impressed by the exaggeration done about Google PageRank (PR), some of my clients and friends ask about the importance of Google PageRank (PR). Rather than giving my personal
opinion about it, I am quoting Google here. These self explanatory replies are by Google/ Google employees.
Best answer - Susan Moskwa (Google Employee) Go to this answer
We’ve been telling people for a long time that they shouldn’t focus on PageRank so much; many site owners seem to think it’s the most important metric for them to track, which is simply not true. We removed it because we felt it was silly to tell people not to think about it, but then to show them the data, implying that they should look at it. 
Source: http://www.google.com/support/forum/p/Webmasters/thread?tid=6a1d6250e26e9e48&hl=en
Google Webmaster Help
Q: My site’s PageRank has gone up / gone down / not changed in months!
A: Don’t worry. In fact, don’t bother thinking about it. We only update the PageRank displayed in Google Toolbar a few times a year; this is our respectful hint for you to worry less about PageRank, which is just one of over 200 signals that can affect how your site is crawled, indexed and ranked. PageRank is an easy metric to focus on, but just because it’s easy doesn’t mean it’s useful for you as a site owner. If you’re looking for metrics, we’d encourage you to check out Analytics, think about conversion rates, ROI (return on investment), relevancy, or other metrics that actually correlate to meaningful gains for your website or business.
Source: http://sites.google.com/site/webmasterhelpforum/en/faq–crawling–indexing—ranking#pagerank
