I've got two videos which I find both inspiring and encouraging so take a look!
The first shows that an autonoms hexcopter can do a very stable GPS Hold, meaning the hex using just GPS can stay in a fixed position in space. The hex then returns to "Home" (in this case it is marked by a mushroom) and lands within a couple of meters, still only using GPS.
Now take a look at this video which shows just how quick, manovoreable and nimble one of these machines can be! This area of technical developement is progessing so quickly it blows my mind on a weekly basis.