I beg to differ…:dajudge: :angel:
PR is not meaningless, it’s just missunderstood.
As I mentioned above, PR is div into 3 categories:
Low, Medium and High, and this is how important your page is. Not how relevant to a keyword you page is. – you might think your page is of high importance for “gambling” but Google might think it’s for “blackjack games”, therefore if you have PR8 – you might show top for blackjack games, but not for gambling… Or Google might think your PR8 is highly important in general, but not for any specific keyword – therefore your PR8 home page ranks nowhere in top results, but inner pages linked from your home page do.
Here is an example to make it easier:
xhttp://www.gamblingphd.com/news/index.htm PR7 – ranks not so good.
xhttp://www.gamblingphd.com/ PR5 – ranks good
Sorry to the PHD-dude 
And I did not say that Sitemaps will help you get high PR, but that Sitemaps will show you in which of the 3 categories your newly indexed pages will fall.