* If this becomes popular it has the potential to skew logs and stats. Consider what happens when a bunch of prefetch requests are made to one of your pages, but the user never actually visits the page. The server (or stats package) doesn’t know the difference.
To clear this up, Firefox sends along an HTTP header, X-moz: prefetch, but you need some logic on the server side to detect it.
Javascript on the page isn't run until you actually visit the page, so that will be unaffected.
I don't think this is a big issue since JS-analytics are already superior to server-side log-analysis (caching alone).