I know this is a little bit of a bump, but I feel like my 2 cents has a lot of weight here (since my job in the Marine Corps is UASs).
I can't speak for the other branches of service but from the Marine Corps perspective on this is that they do not want to phase out manned aviation any time soon. From this point now, the Marine Corps is not expected to receive Group 4 and 5 (which are the Predators and Reapers) UAS until around 2020. There is a bunch of reasons for this and I'll explain:
1. One of the biggest concerns is that the Marine Corps has with UAS is to try and phase out the smaller UAS, Shadow and Blackjack (which mind you the Marine Corps is just finally starting to phase out the Shadow with the Blackjack) to trade in on the Group 4 and 5 UAS. With that will phase out the enlisted UAS pilots. For one, they do not want to do that at this time just due to the fact that the enlisted pilots do a fantastic job at the Aerial Recon portion of UAS.
2. The Marine Corps has only just started to send their officers to the Air Force RPA (Remote Piloted Aircraft) school. As of current there are only about a dozen Officers that are qualified to fly Group 4 and 5 UAS. So as small as the UAS community in the Marine Corps is (maybe only about 200 enlisted UAS pilots), it's even smaller for RPA's.
3. The biggest and most major concern for the Marine Corps is the JSF (F-35). They literally just spent billions in the last two years to upstart the JSF program. Although the JSF can be unmanned, the Marine Corps will never use it in that way.
So in reality:
Aerial Recon: A must for the Marine Corps, and will continue to happen.
Air to Ground Strikes: Not expected to happen until at least 2020 for the Marine Corps. Laser guided bombs can be hosted with the current UAS that the Marine Corps has, but no UAS in the Marine Corps actually has any bombs attached.
Air to Air: The technology is there but probably won't happen until far later down the road (2028 or later).
If you guys have any questions about the particular UAS that I fly, I'm more than open to questions.
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EDIT: a little bit more info for you guys. any UAS bigger than an R\C plane is not allowed to fly in national airspace. Hope that relieves some of you guys.