We (Phobotic) are developing an inspection specific, long range gimbal payload (EO, IR and other sensor options). Its a significant market, perhaps the first real place commercial drones can make actual money. Powerlines, rails, mining, oil and gas, all require good coverage and willing to pay.

Oil rigs are one thing (they are relatively small), but if you want to inspect piping over a long range there's a real challenge with getting usable data out of your sensors (without having to fly the drone within yards of the surveyed object, of course).