According to Techworld.com,  Vista has a new Vulnerability that could let a hacker infect a Vista machine with a rootkit.  The talk from them is quite intriguing.   I will quote it to better let you know what the Vulnerability is:

The vulnerability could allow a hacker to install a rootkit, a small piece of malicious software that is very difficult to detect and remove from a computer, Unterleitner said.

[ad#ad2-left]Phion notified Microsoft about the problem on 22 October. Microsoft indicated to Phion that it would issue a patch with Vista’s next service pack. Microsoft released a beta version of Vista’s second service pack to testers last month. Vista’s Service Pack 2 is due for release by June 2009.
[via Techworld.com]

The way they could do this is through the Device IO Control which in turn could corrupt the Kernel of Windows Vista.  Now we all know that Microsoft will release a patch quicker than 6 months away.  According to this article, people are already looking for the exploit and want to know more about it.  I would be willing to bet they will have a patch out sooner than later.  Probably January or Febuary, which will be a big deal because no one will expect it.  I would also imagine hackers will start trying to figure out how they could install software as quick as possible before Microsoft pushes out the patch.   So what can you do to protect yourself, Get a firewall, a Antivirus and learn how to protect yourself to prevent yourself from getting a computer virus.