tells cast that he is working on what is next after series finale

In the audio commentary that ran during the final episode's ending credits on the sixth Puella Magi Madoka Magica Blu-ray/DVD volume, writer Gen Urobuchi discussed his thoughts for the story afterwards with the cast:

Urobuchi: I haven't been working in animation very long, but they let me do the project the way I wanted, so I really enjoyed it … So, to give my gratitude to everyone on staff for letting me do as I please, I'm doing my best on what's next. Cast: A second season? A second season? Cast: Madoka's … Cast: No, no … Urobuchi: I think I can announce it someday, but I'm trying hard to squeeze the ideas out of my mind. I'm doing my best. Cast: It's got to be a different ending, such as a parallel world from this one, right? It'll have to be … I guess. Is it possible that we can see such a world? I'm looking forward to it. Urobuchi: Well, I feel it hasn't ended here, not yet.

In a magazine interview published in March, director Akiyuki Shinbo revealed that he wanted to do a "Madoka 2" project as a side story to the anime series. He added that if he can, he would like to do a second season or a side story of their characters' daily lives.

The anime ended in Japan on April 21 after being pre-empted out of "self-restraint" in the aftermath of the Great Eastern Japan Earthquake (Higashi Nihon Daishinsai) disaster. Aniplex of America will be releasing the anime in English.

[Via Moe Ota-News Sokuhō]