gistfile1.m

// Update: The plot thickens! In a Mac project you get the behavior outlined below where dragged and dropped 
// IBOutlet property creation yields (assign)'ed properties. In an iOS project however, dragged and dropped 
// IBOutlets get created thusly:
@property (retain, nonatomic) IBOutlet UIButton *someButton;

// -- Original post begins here:
// Since the inception of properties I've written IBOulet properties like so:
@property (nonatomic, retain) IBOutlet NSButton *someButton;

// Today I dragged and dropped from interface builder to my header file in Xcode 4 to create an outlet and got this:
@property (assign) IBOutlet NSButton *someButton;

// Given that atomic properties get extra thread-safety in their generated accessors it has always made 
// more sense to me to have nonatomic accessors and save on the overhead. As such I was surprised to see 
// that atomic IBOutlets are the Xcode default. The question I have is: why is atomic the Xcode default
// for IBOutlets?

The rumor is that it's just different styles between the App Kit and UI Kit teams and how they decided Xcode should handle these things.