I read a lot about search engine positioning, I own a few sites, have targeted big words and small nche words, and I work with a lot of sites that do rank for huge terms, or are well known and well branded.
I’ve seen sites earning big $$ with no pr, ranking very high. I’ve also seen the opposite of that.
One thing I do notice is that most PR5+ sites rank very well, for pretty much everything they post. I’ve seen PR5 sites put up a blank page, because they later intend to put content on it. So, it’s a url, with a template and a link pointing to it. .. they rank #1 within 3-6 days.
I don’t know however if that has anything to do with the PR, if the page has high PR so it ranks well, or if it has high PR because it ranks well.
.. In more random thoughts…
The value of PR seems to change as often as the toolbar.
Throughout one span, it will seem that PR is up.. way more people are happy with their PR than mad.. in the next sweep, the opposite.. the bars go down across the board.
PR6 and PR7 gambling sites are very very rare (ftp actually got a 6, go us.), and rank really really well, but again, whatever seo work was done to get a pr6 (like garnering lots of backlinks, optimizing keywords, checking spelling and code.. ), also helped to boost that rank…