When I say driverless, I'm not precluding the presence of an operator.

John Deere's iTEC Pro, for example, is capable of controlling the tractor, but still requires an operator to be in the cab, just in case. Although here's a fun video of someone who disabled the safety sensors: http://www.youtube.com/watch?v=zU4liQvrcm4

I don't know of any large operator that isn't using at least autosteer, which, for things like cultivating essentially is driverless. For what it is worth, I come from an area of grain farmers.

Thanks for the link. I should ask around to see who is using these. edit: sounds like i'm wrong, they ALL are using automated equipment. they just sit on the tractor, too.