But how soon will they have a prototype of a pilotless, hypersonic unmanned aircraft? Possibly next-generation ramjet engines for speeds of MACH-6 or higher, half the size of a piloted aircraft.
It's also vital that they be low cost, so we can have fleets of such aircraft all in the air at once. Some one-way expendables, most advanced dogfighters and anti-missile aircraft.
They are already planning for the F-35 to have a pilotless configuration. Read this.
http://www.air-attack.com/news/news_article/1980/Lockheed-Eyes-Unmanned-F-35-Amid-Push-Into-Drone-World.html