This episode starts with a nice touch - neatly wrapping up the Lex Luthor plotline from the Superman Animated Series, which is somewhat of a relief: it's about time he was brought to justice. Watching Lex get away with it episode after episode (and comic book after comic book issue) gets tiresome after a while. Now if they'd just follow up on some stuff from the Batman animated series as much as they do with Superman here (and later in Twilight)
After that it's Lex's show. One supposes he hid away a lot of money elsewhere (or he's just bluffing the other villains and can't pay them), but each of those villains gets their little moment. If anything, the episode is a little too rushed. All the villains get _are_ little moments. This is probably inevitable, given we've got all of them and the Justice League en masse.
The Ultra-Humanite fares best (and stuff here foreshadows his final fate in part 2). The Shade is well done, altough he's a pale *heh* shade of his current comic book incarnation as an immortal hero/villain. Solomon Grundy is a big tough brute kinda played for laughs. Cheetah doesn't get much to do here, and Copperhead isn't given much time before he becomes capture-fodder.
And the last few minutes give Joker. Mark Hamill tends to upstage everyone, unfortunately - a credit to the actor's voice-presence. Only Clancy Brown can really hold his own (he had plenty of practice in the "World's Finest" episode :) ). The Joker captures Bats pretty easily, but we find out why in Part 2.
While this is mostly a villain episode, we finally get to see the League in action as a full team for the first time since the premiere movie and this is more the kind of thing they should be doing in this reviewer's opinion, rather than these 3- and 4-member team-ups. Hopefully we'll continue to get more full team efforts. While not everyone gets the screen time you'd hope, the writers do a great job of balancing seven heroes and eight villains.