This seems to be the follow up to http://paulgraham.com/mean.html where pg refines his argument.
I'm glad he did, I felt that his "Mean people fail" essay to be one of his weaker essays, and judging by the comments it got when it was released so did pretty much everyone else on hacker news:)
I tend to agree with him that good people get further along in life. In my industry, finance, I tend to see that the good people do much better than the assholes, contrary to what hollywood would have you believe:)
I think the reason for this is similar to what pg pointed out, finance is a very information and relationship driven business, the better caliber of friendship you cultivate the more people there are who will give you the first call, or preferential treatment on new issues.