Though he was torn about returning to the franchise, EW is reporting that Disney chairman Bob Iger has confirmed that Avengers writer/director Joss Whedon is officially signed on for a sequel to the film. The news was revealed during a conference call about Disney's quarterly earnings.
Additionally, Iger stated that Whedon is in the process of developing a live-action series based on the Marvel universe - could it, perhaps, be this upcoming show for ABC? - but didn't give any further details on the project.
We'll keep you updated with news about both of these developments as it becomes available. For now, however, rejoice!