Windows Vista is still capable of running most Windows XP viruses.
But, due to the new default security settings, it is more difficult to 1)
get infected and 2) for the virus to do system-level damage. However, these
settings won't stop a virus for getting on your system if you give it
explicit permission to run from the security window.
Virus protection is still strongly recommended
Also, I haven't heard of a virus targeting SPECIFICALLY Windows Vista. I
doubt many will until Vista is being used by almost everyone, like Windows
XP is now.
- JB