Wow, this was great. Very funny, and very touching. I can't believe the show's writers had the guts to let Krusty stay married (for now). That was unexpected and just...cool. That kind of stuff is one reason why The Simpsons owns Family Guy.
It was neat, and kinda sad, to hear Eartha Kitt's wonderful voice one last time. And Jackie Mason was back as Krusty's dad, that was awesome.
I cracked up when Bart and Millhouse reacted with disgust and horror at the Princess-ing of Krusty's show, yet for some reason they couldn't stop watching. And I loved it when Lisa freaked out at the "unicorn", and when Bart pointed out that it was just a horse with a fake horn, she hissed at him "Let me have this!!!!"

Really great one-liners: Bart: "Girls ruin everything!" Homer: "Oh, Bart, you say that now, but when you're an adult, you'll just think it." And the blackboard gag was funny too: "The world may end in 2012, but this show won't."
Loved this episode. Two thumbs WAY up!