It would appear as if both www and non-www versions of websites are no longer being treated by Google as separate pages, at least where Page Rank is concerned.
We know that the visible PR in the tool bars is only a loose indication of a site’s actual PR, but it can still be frustrating when you see a low PR for the non-www version, and a higher PR for domains with the www. Recently we have noticed that the PR displayed is now the same for both versions.
I have checked out a few sites where I know the non-www version was displaying a lower PR, and now all are equal. This is certainly a good thing as it is likely a step in the right direction where having both versions will not present any duplicate content issues.
Until such time that duplicate content is no longer a potential hazard, it is still highly recommended to use mod rewrites to permanently 301 redirect traffic to one version of your site. This will eliminate the duplicate content concerns when pertaining to www issues. If you currently use a Google Webmasters account, we also recommend you select the preferred domain to have the site displayed the way you want. For more details on how to play it safe and consolidate www and non-www links here is a tutorial published exclusively at WilsonWeb.com and written by Ross Dunn.
In virtually all situations sites which are visible with both the www and non-www versions are not attempting anything fishy, so it only makes sense that Google should treat both versions as the same URL.