I previously wrote about breaking the old pattern of writing viewDidUnload. The other half of that is the new reality, which Joe Conway’s written about in View Controller Lifecycle in iOS 6.
This is a bit obscure, but I ran into it earlier this week. Why would a view controller appear in the wrong orientation on startup?
A lot of people misunderstand the point of viewDidUnload. That’s because despite the name that implies otherwise, it is not the counterpart of viewDidLoad.