So last night we spent with Mimail, Mydoom and Netskies. Today so far we've been fighting with a minor .S variant of Blaster (aka Lovsan) as well as a new Dumador variant (Dumador.Q).
There seems to be a lot of code-sharing going on. Open source viruses, perhaps? In fact, the source code of Phatbot is now circulating in the underground, and it starts with this: