Based on the podcast with wordlballoon. Below are some of the the highlights:
On Ultimate Spider-man, Jeph Loeb stated that the show was not specifically written for younger audience. It was meant to be a funny show where Spidey talked to the audience and the audience gets to see what Spidey imagines. Jeph Loeb then stated that the ratings prove to Marvel that the show is working, and until they feel that audience wants the tone to change it is here to stay, sort of.
Jeph then talked about the upcoming
Hulk and the agents of SMASH, stating that it is a fun show and that it has no comic book to fall on, stating that fans can't compare it to a comic book version (like how everyone did with Ultimate Spider-Man). The show will be "bombastic" and, hopefully, sends an message to the world that the Hulk is a hero.
Marvel Avengers Assemble was the next topic, revealing that its concept is to feel closer to the movie in term of characters, tone, look and fun. Jeph then stated that they transitioned from Earth's Mightiest Heroes(EMH), and that everything on EMH is acknowledged and still has happened.
The animation on the show is absolutely beautiful. And Unlike Avengers Earth's Mightiest Heroes it will not be rooted in the comic book world but more into the a movie feel (not the movie world).
Jeph then mentioned that according to a research (and not him) that people prefer stand alone episodes rather than long story arcs, and that is the reason why the Avengers EMH format was changed in the second part of the second season. Loeb mentioned how he loves long story arcs, but the networks don't.
If you have time, make sure to listen to the full podcast as it is really interesting and offers a lot of information about Marvel animation division.