How to develop or migrate apps for iPhone 5 screen resolution?

Question

The new iPhone 5 display has a new aspect ratio and a new resolution (640 x 1136 pixels).

What is required to develop new or transition already existing applications

Answer 1

It's easy for migrating iPhone5 and iPhone4 through XIBs.........

UIViewController *viewController3;
if ([[UIScreen mainScreen] bounds].size.height == 568)
{
    UIViewController *viewController3 = [[[mainscreenview alloc] initWithNibName:@"iphone5screen" bundle:nil] autorelease];               
}    
else
{
     UIViewController *viewController3 = [[[mainscreenview alloc] initWithNibName:@"iphone4screen" bundle:nil] autorelease];
}