Well this generated more than I thought it would......
Most comments seem to state a belief that UAVs are not armed, well one of the prime reasons I asked the original question is that they are now armed. A Predator has succesfully fired Hellfire and hit real targets.
Much has been mentioned on not having a pilot would mean a loss of flexibility in response to arising situations. Well most of the more complex have multiple means of data passage to its operators, to overcome reduced bandwidth.
I believe that we will see a combination of both manned and unmanned. Read the following and you will see how close uncle sam is getting.
http://www.mat-kmi.com/features/1_2_Art2.cfm
Sensible discussion on Pprune I don`t believe it !