Jeff Jones from Microsoft keeps hope alive that my Windows Vista system won't be hacked by viruses exploiting new bugs. He just released his Six-Month Vulnerability Report, covering all of the major OSes. He finds that Vista is still the most secure OS to date.
Normally, I would talk about this more, but I'm still compiling the data from all of his reports to draw some of my own conclusions. In the meantime, you should check out what he's already put together, it's pretty cool.