I am sure it is reported elsewhere, but I found an article on a proof of concept virus that targets AMD processors on a magazine site in Australia.  The article dismisses the threat of such an item and pretty much holds it up as just a curiosity in the fight against hackers, but I see it differently.

In order to win, eventually security has to be hardware based.  The whole Palladium (now known by the horrible NGSCB acrynym) effort is just the most public manifestation of this realization and even it has gone dark.  Hacking the hardware is hard, hacking the software is easy.  Software provides the security of a screen door while hardware security done well can be like a steel cage.  Watch as this develops.  Like gas prices driving the frantic (and belated) search for alternative fuels, it will be a mind blowing security threat that finally forces us to invest in security via hardware in real terms.

If the barrier to enter the hardware market in a significant way weren't so large, I expect this problem might already be solved...