Comcast is beginning the launch of a new service to notify users when of compromised computers and botted machines. The service, called Comcast Constant Guard, has started an initial roll out in the Denver area.
Infected customers will be notified via a pop-up message in a browser, and given links to go to the Anti-Virus Center to repair the problem. This will give notification to those not protected by AV software or have been compromised despite. The program will also add another layer of defense to an internet ravaged with growing threats.
It appears as though you may need to have the Comcast toolbar installed for this program to work. So protection would of course be limited to those users. Some users may not see the point in having more than their favorite toolbar installed, especially novice users. Be on the look out, as we may find criminals taking advantage of this to redirect users to Rogue AV or other exploits.
More information on the InSecurity Complex blog:
http://news.cnet.com/8301-27080_3-10370996-245.html?tag=mncol;title