Um... I think you're wrong.
Nickelodeon keeps churning out new shows. Granted, they're cartoons, but they're still shows. Nickelodeon is THE kids' network. Viacom owns them. The NBC people. Disney is ABC. They aren't going anywhere for a while unless Disney BUYS Viacom, which I don't see happening anytime soon.
Oh, wait, you're just talking about the shows on GAS, all of which are at least six years old. -_-