Also - playing games like Madden - you can have a playbook on your tablet, and thus keep the other team from seeing the type of play you are picking. There are a ton of games that benefit from the 'second screen' without busting immersion.
I agree that Skyrim should skip the second screen, but imagine using the iPad as the map from CoD or BF3 - issuing commands to squads via the iPad while they control their characters with normal controllers.