Quite a few posts back when everybody was back slapping each other over Chinas J20 one member posed the question "what of Europe" with the financial crisis they will be too poor to develop anything to match or counter the J20.
Although not in the design class of the J20, how about the UK's Taranis. Its a unmanned fast Jet demonstator, the size of a Hawk trainer.Its one of the worlds largest UCAV, that is stealthy, travels vast distances. While primarily built for survellience, it also can deploy a range of munitions over selected targets as well as defend itself against manned and unmanned craft.
Just imagine if different variants were built such as specialised J20 hunter killers. Lacking a pilot, so t you could pull more G's, thus making it ideal for dogfighting and all that sort of stuff. And after expending all the muntion one could kamikaze it into an enemy plane.. Sacrificing one cheap UCAV over a more expensive and crewed J20 would be a pretty good swap huh?
Taranis Unmanned Combat Air Vehicle (UCAV) Demonstrator - Air Force Technology