If I was DC, I'd seriously be pissed off about how Cartoon Network is treating their shows; Batman:TBATB randomly has scheduled episodes yanked at the last second and vanishes from the schedule for six to eight months at time. Beyond that, they can't even be bothered to replay those new episodes either. If you miss that one new episode, tough.
I'm afraid that the same thing that happened to Generator Rex will happen to Young Justice; the show comes out, is a massive hit, takes a several month delay with scheduled episodes being taken off that schedule at or near the last minute, and the ratings collapse. The Clone Wars not being on right now hurts the Friday action block, but I can't help but think that that show's continued success is largely due to the fact that, barring special events like Christmas programming, it had a season that was relatively uninterrupted from start to finish.
Giving Adult Swim that 9 o'clock hour has been a disaster for the rest of their primetime lineup. Ratings are a full point lower than they were before then.