GoogleGuy: regardless of whether you're pretty sure I'll click on the top result, how do you know I want the page to be prefetched? I'm on broadband so the few ms that might be saved are irrelevant. And the times I'm likely to be on dialup are also times when I will probably need the bandwith for stuff I _definitely_ want to load.
BTW: I think prefetch can be a useful idea, but should be an optional extra for those who want / need it. A large part of the problem is not so much Google using it, but Mozilla for enabling it by default.