The latest game by Gameloft called Order&Chaos starts with a Checking for Update screen, which indicates that they’re able to update certain data without updating the entire binary.

I’m quite certain that they’re using some kind of scripting language like Lua in their app and updating these scripts to e.g. change certain values (like buying price of items).
What’s your experience with side-loading or updating scripts in your iOS application?
I don’t mean loading new graphics or other contents, but game logic like my path finding implementation in Lua.
Apple cleary states that this isn’t allowed
3.3.2 An Application may not download or install executable code.
Interpreted code may only be used in
an Application if all scripts, code
and interpreters are packaged in the
Application and not downloaded. The
only exception to the foregoing is
scripts and code downloaded and run by
Apple’s built-in WebKit framework.
This happens in most of these applications TinyChef, RestaurantStory, HotelStory, etc..
They update content, but not the core program. Just adds new content or modifies the existing using external files and DB updates from a remote server.
Example, what they do is download new graphics and add a new item to their Desserts table of their DB and finally when they show all their Desserts the new one shows up and its ready to be cooked as if it was in the app from the beginning.
I could elaborate more info if you need.
UPDATE
If you are using lua, you could easily add, say new levels to your games, just by downloading a file containing your level data. Im sure that you are familiar with using external files one per level/item/character with a common format you then parse in your app.
You can have your path finding algorithm in another file as i said, and update (download and replace) that unique file whenever you improve it.