This isn't news. Google will add a link tag and prefetch directive to links that it's confident you'll click on. There's a greasemonkey script that will identify prefetched resources:
No, they're not doing that, it's Firefox's pre-fetching that does that. It's fetching parts of the linked sites, and in doing so, the site is trying to set a cookie.
[+] [-] mqt|17 years ago|reply
http://userscripts.org/scripts/show/38841
[+] [-] snewe|17 years ago|reply
http://inertcom.com/goog_cookie.png
[+] [-] slater|17 years ago|reply
Google has nothing to do with this.