Nothing obvious has to happen on your computer. The worm could be collecting information and sending it on. From what they've been able to determine, the worm was designed to obtain new instructions today, but they may not be triggered until later; they may only help it to hide and embed more deeply for the time being.

If Microsoft created the virus, it would probably break down on its own. It would be more likely that evil geniuses at Apple, Sun or Debian created the virus, because they're actually competent, and stand to gain more if people defect from Windows. Microsoft doesn't need to create such a virus--it already has y'all by the shorthairs.