1) highly maneuverable remotely piloted vehicles are very much still in development. Modern militaries have a strong interest in developing these weapon systems.
2) Forget Area 51, think Plant 42. Plant 42 is the home airfield of Lockheed's Skunk Works, Boeing's Phantom Works, and Northrop's 'Site 4' as well as NASA Dryden. The Raptor, JSF, X-32, X-45, X-47, and many MANY other secret modern aircraft/aerial vehicles were developed at Plant 42.
3) HiMAT was more of a test bed with no intention of becoming an actual weapon system. Specifically it was made to be a highly modular test platform to allow for testing of a wide variety of configurations of flight control surfaces. Currently the them with remotely piloted UCAVs centers around doing the '3 D' missions: The 3ds being Dull Dirty and Dangerous. The other up and coming goal of UCAVs is the swarm. The common idea being one manned high capability fighter (like the JSF, Raptor, etc) would be linked with many other UCAVs. Thus the fighter pilot would control the UCAVs to coordinate the mission.
In closing, the #1 advantage of a future UCAV over a manned fighter is G tolerance. All modern fighters are pretty close in maneuverability because they are all limited by the G load of the pilot. The Raptor for example is capable of well over 20 G's, but if the Raptor pulls 20, the pilot will be crushed to death. So take that pilot out and now you have a fighter with many more times maneuverability than ANY manned fighter.
If you cant tell, this stuff is a bit of an obsession for me...may have spent one to many long nights reading defense reports...

No kidding !! have you got to smell an aliens fart?? what are they like?

but really... do you think they have made anything like an unpiloted raptor? I never knew it would be able to pull That many g's.. I used to... and still do play F 22 ADF (and total air war) (a game from 1997, 1998 made by DID) but in that game it maxed out at 10 g's or so (due to pilot blackout) I was never sure if that was the planes limit, or the planes Fly by wire max G setting. Never actually looked it up.
Butbut I was looking up synthetic vision, and learned that technology has been in use for over 30 years, and there was a reference to HiMAT, which brought up the thought "why hasn't the military made much progress towards unmanned fighters"
Not knowing a lot about what is required, but seeing some of the other tech out there, you think there would be more progress in this sector. The advantage of an unmanned fighter (or even a bomber) would be overwelming for any conventional piloted craft.
I realize the biggest problem would be actually controlling the aircraft, due to lag, if it were satellite controlled there would probably be "pings" of up to 500ms.
but that could be brought down to an (estimated) 150ms response time with nearby AWACS. It has been a well known fact that there are arcraft to aircraft wireless networks, that share information such as radar contacts, targets, and waypoints. I have known about that tech since I was 8 (15 years ago).. I don't know when it actually came out, but its at least 15 years old... and if my internet connection has gone up from 33.3kbps data modem to 8mbps cable connection, I can only guess how far the military has gone with their wireless tech. Although the speed of light will be a limit for some time still I would guess.. (unless were with the ailienzz)
but even with a 150ms ping... with a much more manoeuvrable plane, that would probably take 9/10 of its targets from BVR, I dont think it wouldn't be much of an issue.