Watched it last night with the kids, who were crushed by the idea that there would be no more JLU. The last two seasons have been far and away the best DC animated work, IMO. Not to take away from some of the Batman single eps, but I don't recall a whole season that hangs together quite as well (that's Timm Batman, not the gobbeldygook that's going on now).
The seven year old boy, six year old girl, and 34 year old dad were bouncing off the walls with the "Superman SMASH!" moment. AWESOME. "I never really get the chance to cut loose and show you HOW POWERFUL I REALLY AM." I've got to go and memorize that speech--classic!