It looks like Google wants you to think PR doesn't matter, but don't let them fool you! For more than a decade now, Google has been trying to retrieve this metric from the radar of webmasters. That Google has stopped pushing regular updates to their toolbar is one more step in the strategy to convince you that PageRank doesn't matter anymore.
Balderdash. Let's look at the trouble Google's gone to pull the wool over our eyes.
PageRank wasn't unknown to webmasters in Google's in the late 90s, but the search giant really spilled the beans on PageRank in December 2000 when it released the Google toolbar that included the metric that Google still describes today as "basis of Google's search technology."
Google knew that the metric would be of vital – and viral - interest to webmasters and webmasters not only flocked to install the toolbar, they began using the metric for link swapping, selling and buying. It made PR manipulation so much easier when you could easily see Google's estimation of the importance of a page.
Google has been backpedaling ever since. Unhappy with the manipulation of PageRank that was greatly enhanced by the ability to see the PR on any page, (but apparently unwilling to withdraw entirely the prime reason to keep the toolbar installed on your browser), Google fought back with a publicity campaign and with tools that sometimes backfired.
For example, in 2005, Google introduced the nofollow attribute to fight comment spam and encouraged webmasters to add it to their blogs. Not long after, they demanded that anyone selling text links use the nofollow attribute to discourage selling PR.
This handy attribute opened yet another can of PR worms for Google, as webmasters quickly learned how to apply to sculpt PageRank within a site and Google engineers had to change the way that Google divides links on a page to prevent webmasters from reassigning it with the use of nofollow.
Google stopped pushing data to the toolbar in late 2004 and established something of a quarterly schedule of updates with the hope, one assumes, that outdated PR would devalue the commodity. "The PageRank that is displayed in the Google Toolbar is for entertainment purposes only," Googlers reportedly announced that December.
In October of 2009, the ability to see the "importance of a page" was removed from Google's Webmaster tools in the search giant's ongoing campaign to take the focus off the PR metric, and 6 months later in April '10, released what appears to be the last quarterly update. Webmasters report updates to toolbar PR often with no pattern, as though updates are now simply random and sporadic.
Google does seem to have effectively rendered the toolbar more useless than not, and it's common to hear many webmasters insist that PageRank is no longer important.
Again, I say, balderdash! If PR wasn't still a central factor in Google's algorithm – or as Google puts it, the basis of their technology -- why would they go to all this trouble to pretend otherwise?