Here’s an interesting tidbit from MessageLabs’s september report: on the day that the alleged malware hoster Intercage was taken offline, there was a significant drop in malware activity: 

The drop was very shortlived; this suggests that Intercage was primarily hosting C&C (command and control) servers that control the activity of the botnets used to send spam. MessageLabs agrees with this:

It can be seen from the chart above that the botnet controllers are quick to respond to any degradation of their service, and can re-point their bots at a new command and control channel in a matter of days.  Therefore MessageLabs expects this decline in spam to be short-lived, especially in anticipation of Halloween in October and Thanksgiving in the US in November, both of which are traditionally seasonal favorites for spammers.

You can find the complete report here.

YARPP