There's been some follow-up letters regarding the article, showing up in the latest issues of Proceedings
. One respondent pointed out that the Global Hawk sensory package is limited compared to the U-2, and that the original author miscalculated the costs of planned development, which is really about three times the quoted cost.
The most recent responses indicate that both UAV and manned recon is vital together, and should not be separated. Narrowness of field of view is stated as a possible weakness of UAV recon. Also, it is pointed out significantly, I think, that the UAV costs more than manned since the costs of production combat aircraft go down during production runs with only costs to be added for recon modifications instead of a complete vehicle.
Most significantly, it was pointed out that the UAV's in US service experience mishaps or get destroyed 20-50 times greater than all manned aircraft! Even lower when compared to manned recon.
Looks like manned recon is here to stay for a while.