Broken Base: Over the decision to save Scott Lang from his death during Avengers Disassembled via time travel. The aftermath is treated as still being part of the 616 universe, even though normally such an action would result in the creation of a new spinoff universe. People who like the character or dislike Bendis's work on Avengers consider it an Author's Saving Throw, but others accuse it of being Armed with Canon.
Development Hell: The first volume of Young Avengers ended in 2006 with the team planning to search for the Scarlet Witch. This story was supposed to be done in a second volume of Young Avengers, but because of Allan Heinberg's busy TV writing schedule and changes in the Marvel Universe status quo, the story never actually got done until 2010.
The Woobie: The Young Avengers, but Wiccan and Cassie especially.