Higher PR no longer necessarily means higher SERPs.
Mainly, it means you can charge more for links (if you’re into that kind of thing) – although a lot of sites have been punished in this latest partial update for doing that.
It’s likely that the webmaster you refer to has linked to this new site from a number of existing sites that have good PR. It’s very unlikely that a brand new site would go to PR2.
Content = traffic, with or without PR.
More IBLs means that more pages get indexed and therefore get traffic.