The amount of spam has been reduced thanks to the CAN-SPAM Act, at least according to the Federal Trade Commission's annual report to Congress [.pdf]
Um, what? That definitely is not the case here where I get flooded with spam. (I'm getting more e-mails with Chinese writing these days.) There are a few reasons for that. One is because our e-mail addresses are posted all over the place precisely so you can get in touch with us if you want to. (Some news organizations use forms rather than just having a direct e-mail link to the person. I would rather you be able to contact the reporter directly.)
The other reason is that we had to pull the editorial staff off the corporate spam filter earlier this year because it was preventing e-mail from coming through without telling us.
I don't know what others are finding, but I don't see much reduction in the amount of spam, but I also don't hear feds complaining about spam all that much, so maybe agencies have really good spam filters?