The designated initialiser for UIViewController is initWithNibName:bundle:. You should be calling that instead.
See http://www.bignerdranch.com/blog/real-iphone-crap-2-initwithnibnamebundle-is-the-designated-initializer-of-uiviewcontroller/
If you don’t have a nib, pass in nil for the nibName (bundle is optional too). Then you could construct a custom view in loadView or by adding subviews to self.view in viewDidLoad, same as you used to.