Marvel has announced on their website that 3 more cartoons are currently in production for the nickelodeon channel , The Avengers : Earths Mightiest Heroes (2011) , The Black Panther (2009) and Marvel Super Hero Squad (2009).
And also Wolverine and the X-men and Iron-man : Armoured Adventures will air next year.
http://www.marvel.com/news/.5324.Announcing_Avengers~colon~_Earth~apos~s_Mightiest_Heroes (http://www.marvel.com/news/.5324.Announcing_Avengers~colon~_Earth~apos~s_Mightiest_Heroes)