It's just a joke. Batman's my favorite superhero, and I thought The Dark Knight was a great movie, but... There's a lot about The Dark Knight that is ripe for spoofing.

And really, as much as the Joker is one of my favorite villains, you must admit... In the DCU, he's a tad overrated. The whole "When supervillains want to scare each other, they tell Joker stories" thing. There's a lot nastier baddies in the DCU, some that would make even the Joker say "That's pretty sick."