There needs to be more of an explanation of Kakashi's past. Everyone seems to have the impression that Kakashi isn't that strong because they've grown used to seeing extremely strong guys like Orochimaru and Jiraiya.

Also, I think Gaara has pretty much served his purpose in the story. I wouldn't expect Kishimoto to bring him back unless there's a good reason plotwise. Hell, I think Anko was a cool character, but we haven't seen or heard from her.