Although the fate of Cartoon Network’s Young Justice is pretty clear, producer Greg Weisman doesn’t appear to be closing the door to the possibility of more episodes, even after the show’s second, and presumably last, season comes to a close this spring.
Talking to The World’s Finest fan site about the final issue of his Young Justice comic series, which arrives Wednesday, Weisman said, “I’m not writing an epitaph here. But the nature of the business is that you never know if you’re going to be picked up for more episodes or issues. So whether it’s Captain Atom, Gargoyles, W.I.T.C.H., The Spectacular Spider-Man or Young Justice, I always try to end each season or run at a good place to stop, with what I like to call open-ended closure...”
More at the source.
Source: Spinoff Online
In other words, the show will end with a cliffhanger and we'll never get full closure.