Most SEO and online marketing professionals know the Google tool bar Page Rank stopped being an effective indicator of a websites authority about a year ago. However, there is still tons of sites trying to sell advertising based on their websites "Page Rank" as well as individual companies obsessing about why their page rank has not gone up despite all their efforts of good brand seo.
Though Google still uses PR in the back end of the algorithm, they have said in their typical sideways fashion, they are most likely NOT going to be updating PR again. John Mueller from the Google Switzerland team said this in a video post to the official Google Webmaster channel.
Here it is.
So with that in mind, there will probably never be another official Page Rank update, unless it's by accident as it was according to Matt Cutts regarding the December 2013 update.
What these means is you can relax about PR. Just get comfortable with NOT KNOWING what your official PR is. Instead, stay focused on creating great content, sharing your content and building an audience. Ultimately, if you build a great brand, it doesn't matter what Google thinks of it or not. What matters is the people. And, if people like you, then Google will like you.