Per this CNet article... Microsoft and Unisys are launching a multimillion dollar ad campaign to undermine Unix.
The campaign, called "We have the way out," describes Unix as an expensive trap. "No wonder Unix makes you feel boxed in. It ties you to an inflexible system. It requires you to pay for expensive experts. It makes you struggle daily with a server environment that's more complex than ever," one ad reads.
The irony is a bit thick... but depending on their relative success/mindshare, may affect Apple's future ability to use Unix as a selling point for Mac OS X.
Note: the target of this ad appears to be Sun more than Apple... but still...