Chrome beta does prefetch URLs: download the latest version, go to a Wikipedia page, wait a few seconds then click the first link – it should appear (almost) instantly.
I don't know if it prefetches links in webmail, however, and that would be about the only situation I can think of where this might happen.
Edit: of course, now that I posted this, I can't seem to make it work. I promise it does happen.
GDH: your reply to this comment is not visible: you've been hellbanned. It appears to have been for a comment you made 312 days ago.
Your demo link seems broken, it prefetches a new page every time you mouseover, not just once. Also, there's autoplaying audio ads, something that I can only regard as a bug.
