It is interesting to note that @Stake recently fired their Technology Director for co-writing the widely cited white paper Cyber Insecurity: The Cost of Monopoly. It was said that @Stake has done software evaluation research for Microsoft, which may have influenced the firing.

I understand that these Mac OS X advisories are rather speculative in nature. Seeing the first Mac OS X worm or virus might not be too far in the future, though. But we'll see. We have been waiting for the first virus to appear for several years now.