
A valid question, and one that has puzzled me since I recall seeing screen shots from a gaming magazine several months ago (whenever I fly, I indulge and buy a video game magazine from the airport book stores, the ultimate in guilty-pleasure light reading). Here's
a nice Associated Press article, most of it being speculation, discussing why there was no official video game tie-in for The Dark Knight. There was a mobile phone game, but there was no video game released for any of the consoles.
I'm guessing it was a quality issue since the speculation involving only making games for sure-fire blockbusters is absurd. Speed Racer and The Incredible Hulk had video games, as did Kung Fu Panda and Prince Capsian. None of these films were expected to set any records.

The Batman franchise has had a mixed success history in video games. The Super Nintendo versions of Batman Returns and The Adventures Of Batman And Robin (ie - Batman: The Animated Series) are arguably the best Batman games ever made. But for every Batman: Vengeance, there have been mediocre or downright terrible games (the infamous Batman: Dark Tomorrow is probably the cream of the crap). But, unlike other franchises, most Batman games have been at least enjoyable (I'm fond of the 1991 Atari arcade adaption of Tim Burton's Batman).

I can only assume that The Dark Knight game was shelved because it brought up memories of the dreaded Superman game for Nintendo 64. Released in May of 1999, it was a game so astoundingly terrible that it quickly became the definitive adjective in describing poor video games ('dude, this game is Superman 64 bad!').

On the plus side, there's a good chance that Lego Batman will be one of the greatest Batman games ever created. If it's anywhere near as much fun as the Star Wars and Indiana Jones Lego video games, we'll have a new classic on our hands come Fall.
Scott Mendelson