The quick answer is yes. I recently purchased a new Gateway Laptop. It came with Vista and a McAfee trial. I noticed while looking at search results that there were little green markings. At first I thought it was a "Vista Thing", but turns out it was a rating system by McAfee to warn users of potential spammy / spyware Web sites. I did not like the functionality, so it was disabled. After thinking about it, wouldn't you like to know if your site was not "green"?
This comes to mind because of an email I just received about Spyware still plaguing searches. This article reassured my initial concern that marketers really need to know how popular third party tools may be affecting their links.
If you do not know how your site ranks, find someone with McAfee and make sure you are in the clear.