There seems to have been a major victory in the spam war recently:

http://news.bbc.co.uk/2/hi/technology/7725492.stm

"The closure of a web hosting firm that is believed to have had spam gangs as clients has led to a drastic reduction in junk mail.

Two US internet service providers have pulled the plug on the firm McColo following an investigation by the Washington Post newspaper.

Anti-spam firm Ironport has seen junk mail levels drop by 70% since McColo was taken offline on 11 November."
I was intrigued by this, so I checked the spam filter on my main email account. The system has been wonky for a while and doesn't report good emails properly, but the spam count has always remained accurate. Take a look at this results and note the dropoff at 11/11: