How long before the Eagles make it back to the super bowl?

I'm getting a bit bored with all of the questions about the Lions and Bears, so I figured I'd just ask another type of question. I realize no one knows exactly when the Eagles will be in the super bowl, because it could be next season for all we know. But I am asking for a rough estimation. What do you think it will take for the Eagles to finally win a championship? What will it take for them to compete with others in the NFC (Packers/Bears/Saints)?