From www.commicscontinuum.com:

Cartoon Network's upcoming Justice League animated series will be an hour-long show, the network announced on Wednesday.

As part of a press conference in New York City detailing its plans for the 2001-2002 season, Cartoon Network also announced that Justice League will premiere in November.

According to Justice League writer Rich Fogel, it won't be a case of two half-hour stories comprising the hour.

"All the stories are one hour," Fogel told The Continuum. "The pilot will run 90 minutes."

Justice League is being produced by Batman/Superman/Batman Beyond producer Bruce Timm at Warner Bros. Animation. Cartoon Network has ordered 26 half-hours.

Neither the network nor Warner Bros. Animation has released art from the show yet. A representative said it will be "a while" before art from the series is shown to the public.