I came across this story during my browsing session this evening:
http://www.theregister.co.uk/2013/10/01/ie_0day_widely_exploited/
"Carl Leonard, senior security research manager EMEA at Websense, commented: "Websense estimates that close to 70 per cent of Windows-based PCs are vulnerable to this exploit. Given the huge attack surface, the actors behind these campaigns are racing to target companies before a patch becomes available."
"In addition, we anticipate that as more information of this zero day comes to light, the exploit will be weaponised and packaged into exploit kits rapidly, greatly increasing the number of attackers with access to this exploit," he added."
At the end the author states that Microsoft may have a security patch available by Oct. 8. Hold your breath until then.