Rustock is apparently severely crippled if not dead.  I noticed at least a 30% drop in spam volumes across the networks I manage.  I began looking at feeds, checking other security sites and the rumor was Rustock had been taken down by a concerted effort similar to the one that has crippled Waledac.  Upon returning form recovering a clients hard disk I saw this post from Microsoft talking about the Rustock takedown.  I also found more details about the takedown on Threatpost as well as a podcast on the same site.  Rustock has been one of hte longest lived botnets around. and I’m hoping Rustock is truly crippled or even dead and not set to rise again.