The SANS Internet Storm Center reports that some worms exploiting the new Microsoft RPC vulnerability (MS08-067) are been seen on the wild. As I wrote before (here for the automatic translation by Google) this is critical vulnerability from the same family that brought us worms as Blaster.
Fortunately as mentioned by Steve Gibson in Security Now the Internet has changed a lot from those past experiences. Today most Windows XP (with SP2) and Windows Vista hosts have the firewall on by default that minimizes the risk of infection. However many Windows 2000, 98 and 95 computers, most of them forgotten in some computer room are still in a high risk. I wonder if this will be another endemic disease that will be living in the Internet as their cousins.
Here there is the report from F-Secure for the interested people. And, wait for at least some minor disruptions generated by compromised machines.