When I was first learning Cocoa/CocoaTouch I found it hard to jump from the books I was studying to my own apps. Creating a TabBarViewController, fine. Retrieving location, simple. Creating views and sub-views, there are 100's of tutorials and books with step-by-step code examples. However, when it came time to bring all those pieces together into a real app there was (and still is) a huge gap in available resources.
App architecture, memory utilization, debugging/unit testing and code style are areas that I'd love to have Ash cover.