When I flew into the US (LAX) recently, they made everyone fill out the usual Visa Waiver form (even if you'd already applied online). I have no idea if my online application has actually been used. I suspect (but PLEASE don't rely on this), that either they never intended to enforce the online visas this year, or so many people have turned up without having applied online, that they're having to use the old Visa Waiver method.
When I flew into the US