Well sorta.
THE BATMAN
The season finale featured another superhero from the DC Universe; Martian Manhunter J'onn J'onnz and his alter ego Detective John Jones (Dorian Harewood) when he warned Batman of an invasion by an alien race called The Joining. Batman, Robin, Batgirl and the Martian Manhunter were successfully able to rid the Earth of The Joining.
At the conclusion of Season 4's finale "The Joining", The Batman is taken to an orbiting satellite (resembling the Hall of Justice from SuperFriends) where he meets members of the Justice League of America; Hawkman, Green Arrow, Flash and Green Lantern. Season 5 (starting September 22, 2007) will feature the JLA in major crossover episodes, with Superman and Aquaman also scheduled to appear . Batman will be appearing with the Justice League.
[flash]http://youtube.com/v/Y04HCnOn4r0[/flash]

THE BATMAN
The season finale featured another superhero from the DC Universe; Martian Manhunter J'onn J'onnz and his alter ego Detective John Jones (Dorian Harewood) when he warned Batman of an invasion by an alien race called The Joining. Batman, Robin, Batgirl and the Martian Manhunter were successfully able to rid the Earth of The Joining.
At the conclusion of Season 4's finale "The Joining", The Batman is taken to an orbiting satellite (resembling the Hall of Justice from SuperFriends) where he meets members of the Justice League of America; Hawkman, Green Arrow, Flash and Green Lantern. Season 5 (starting September 22, 2007) will feature the JLA in major crossover episodes, with Superman and Aquaman also scheduled to appear . Batman will be appearing with the Justice League.
[flash]http://youtube.com/v/Y04HCnOn4r0[/flash]