I think that if you do splash a UAV it should count... I mean if you do shoot down another fighter and the pilot gets out and lives it still counts too, right? So a "kill" isn't really defined by loss of life anyhow.
I'm not sure of any UAVs our adversaries currently operate, but downing any enemy aircraft is supposed to count as a kill. Even if you shoot down a cargo plane, you get a kill star on your jet.
In another thread about Desert Storm, we were recently discussing the Strike Eagle's kill of an Iraqi chopper with a GBU-12 laser guided bomb. The chopper lifted off of the ground so it did count as an aerial kill.
Beers and MiGs were made to be pounded!
"He counted on America to be passive...He counted wrong." -- President Ronald Reagan
UCAV will be a different story though.....But remember that WWI pilots were given credits for balloon kills and WWII pilots were credited with V1 kills. Sailors who manned masted warships thought that steam powered warships were stupid. But that didn't halt progress and a new way of thinking.