I personally think that, while UCAVs will eventually take a large part in world's militaries, the fact that, as of now, flying two globalhawks on Iraq takes away half (read it, half) of all sat comm channels, places large scale use of UCAVs very far in the future. But also, if we resort to remote control, look at the can of worms you open:
You occupy a large chunk of the sat channels in any case
You prevent any kind of friendly EW operations (You can't choose what you want to jam, you jam everything.)
You heavily expose yourself to enemy EW operations. Even if the UCAVs can accomplish their mission on their own,
the lack of supervision means that many things can happen.
1st: the fact that the flight plan can be exploided by the enemy.
2nd the enemy can place civilian targets (or construct fake ones real enough for the public opinion to consider them as real.)
on the plane's target area. Hitting them would be perfectly avoided if the supervisor takes over, but if he can't...what happens?
The fact that the UCAVs themselves lose their link with SAT assets telling them where to go is also a big issue. in a modern
war operation you can't rely that much on a simple pre loaded topografic map all the time.
So, while i see manned planes controlling "Squire" UCAVs to support them, i don't see them replacing manned planes ever.
Even if it's just the need to have a human there and able to take over if the link becomes interrupted.
PS. Also, if you add satelites to support drone operations, it takes only a sat killer missile to incapacitate a large chunk of your drone assets. The US military loves drones so much at this time because it has the monopoly on space, and much of their military comm sats cannot be reached by the OPFOR. yet.
my 2 cents.