I feel as though, sometime in the early 2000s, it lost what made it unique and became a generic Children's Television Brand and hasn't really recovered on that front. Really, that kind of started when Boomerang was given its own channel. By 2002 it was really obvious they were slipping, and by 2004 or so I definitely preferred Boomerang.
I'm not saying this as a nostalgia fiend, I am saying this as someone who appreciates the blend of the historic and new. Nothing like that has emerged since, because Time Warner's ownership of the WB/MGM/H-B libraries prevents that from happening, and children's/family entertainment properties are highly sought after and jealously guarded.