The US Navy has said the F-35 is probably that last manned fighter for them. The X-47B is done after the refuel testing so it makes one wonder what is the next test aircraft.
The Navy is already running a big competition for their carrier based unmanned vehicle (UCLASS)[1]. This competition is part of the reason why, I think, there have been regular press releases coming out from Boeing, Northop, et al. and the Navy regarding drone capabilities - carrier landings, mid-air refueling, etc.
No, the USN has said the F-35 will be the last manned "strike" aircraft for them. They are developing the F/Axx to replace the F-18, and this will definitely be manned.
Yes, I should have added strike fighter, but the F/Axx is listed as manned or unmanned. I have my doubts about the duality they think they are going to get. On the technical side the F-35 is replacing the F/A-18C while the F/Axx is replacing the F/A-18E/F Super Hornet.
The problem for the USN is that the F-35 isn't coming along fast enough, and the cost will make the airwing even smaller than currently deployed. I think they Navy would love to ditch the F-35, let the Marines suffer with the F-35B, and push on to F/Axx. Of course the really smart thing would be pushing UCLASS hard, but that would conflict with a lot of their ideas about piloted aircraft.
At this point, they might as well buy the newer F-18 until they can get a decision. It looks like Boeing needs orders or it will shutdown the line.