Spec can't come back as Sony own that show, but no longer have the rights to use those characters. They could bring back EMH potentially - DC brought back Young Justice after a decade long hiatus after all. But I think they're more likely to use the animes as a replacement for Avengers Assemble, especially now that the Future Avengers have appeared in the comics.
It's a shame Rising is just one-shots and not an ongoing series, as that cartoon IS decent.