Thanks to Amazon, we now have further details on the DVD back cover art, which includes the running time of the movie and bonus features. The movie will be 75 minutes long (an updated running time from Amazon's original information, which listed 72 minutes) and the only bonus features will be the two episodes of The New Scooby-Doo Movies which Batman guest starred in ("The Dynamic Scooby-Doo Affair" and "The Caped Crusader Caper"). The movie is also now up for pre-order on Amazon.
Here's the description for the movie, taken from the back cover:
When Scooby-Doo and the gang run into notorious crooks that are too hot to handle, the caped crusader himself, Batman swings in to save the day! After an unsolved case from Batman’s past comes back to haunt him, and the mysterious Crimson Cloak threatens to take over Gotham, Batman recruits Mystery Inc. to help crack the case. Will their teamwork be enough to solve the mystery and foil the plans of the most dangerous rogue villains the world has ever known? Pack your utility belts with gadgets and Scooby Snacks to find out, as you takeoff for a wild crime-busting thrill ride of a caper!