...is any Win2k server, and some Win2k workstations running IIS. At least, those that haven't been patched.
There's a lot of testing going on here, and we aren't license limited. Remember, we do a lot of reinstalls as well, so we get a lot of "new" machines popping up on the network.
Oh, and there is a fix - but you basically have to set up the entire machine and install the patch without being on the network. There are so many infected machines right now that there's roughly a 5 second delta between bringing up a machine and getting infected.