Is it possible to update the iOS background wallpaper now with iOS 7 programmatically? I have several instances where users are wanting to update their wallpaper to a chang
NO. Apps are sandboxed and do not change system settings in any way.
There is not, and will likely never be, a public API for this. This is a good thing, trust me.
You can save a picture to the user's photo album, which should then be easy for them to set that as their wallpaper.