Very timely warning - got one today and I think I have only ever had one other suspicious thing before, so thanks.
Mine was titled 'mail delivery failed' and addressed to someone other than me strangely. The worm did not appear to be in the email but in zip file attachment - which did not get run.
Got the Norton outbreak alert at the same time - but why if I have automatic updates selected does it simply come up with the alert, with a click here to 'protect me' button. That seems like a manual update to me!