Unfortunately, I think the end will be in sight for multiple reasons.
Firstly, as a graduating Eng. student at Manchester, we are more or less constantly being fed UAV projects left right and centre. Our final year group design was involved in creating an unmanned recon aircraft.
The MOD are currently working with around 5 top engineering departments with regards design of a stealth UCAV. Apparently, the benefits of removing a significant G limit from the picture (ie the pilot) as well as the benefits gleaned in a stealth environment from removal of a glass cockpit, the picture looks bleak. Plus, think of the extra sensor suites that become available.
Combine that with removal of political problems occuring due to a shoot-down and you have a much improved package.
Fortunately though, by the time Bae or whoever get to build it get it front line, we will all be on our pensions anyway.