You see these types of threads every day and they make you want to yell. I have a site with a PR4 and over the past 6 months my backlinks and quality (PR) of backlinks have increased exponentially but yet, my PageRank remains the same. What is going on?
Well, nothing you can see in terms of the PageRank bar updating. Case point...This site had a PR6 for over a year, probably over 1.5 years - I don't track this site for that type of stuff. But since then, I have accumulated over 35,000 links or 77,900 links depending on how you ask (more on that in the next entry I post). You will notice the links are from other sites such as Google's Blog, Yahoo!'s Blog, MSN's Blog and so on - so they are pretty high quality. But yet the PageRank remains the same.
We should all just let it go. If your PR changes, great. If not, great! Just don't expect anything positive or negative - like you could have two years ago.