This might be a little old news but this is something that I just discovered recently but Ncircle Entertainment is re-releasing Animation Station DVDs. Animation Station is the company that released single disc DVDs of some classic DIC shows. They released Super Mario Bros: King Koopa Katastripie which contains 6 full cartoons of The Adventures of Super Mario Bros 3 and a bonus episode of Sonic Underground. They also released Sonic Underground: Dr. Robotnik's Revenge which includes 3 Sonic Underground episodes and a bonus episode of the Super Mario Bros Super Show (with the Mario All Stars intro and outro).
I found this out when my friend went to Best Buy and he got the two pack DVD of Super Mario Bros: Mario's Movie Madness/Sonic Underground: Dr. Robotnik's Revenge which is the rerelease by Ncircle. When you would previously own these DVDs they would have the "Animation Station" logo at the top. Ncircle DVDs leave that out, they also leave out the message on the front case saying that it includes 4 episodes of this show or something like that. They also have some different changes in those rereleased. One of the things they changed is that they took off the bonus SMBSS episode on Sonic Underground: Dr. Robotnik's Revenge. Also Ncircle entertainment is gonna rerelesed Super Mario Bros: King Koopa Katastripie on Augest 21, 2007. They're also gonna re-release Sonic's Christmas Blast on Octobber 23, 2007. They also re-released other Animation Station DVDs such as Inspector Gadget, Heathcliff, and Jayce and the Wheeled Warriors. I don't know if they'll do anything new for their DVDs, we'll have to wait and see.