By now you already know that WordPress 3.4 has introduced a ton of great features (because you always perform core updates, right?). One of the coolest new features is support for Flexible Header Images. Remember in the dark ages of WordPress, when you had to crop your header image to fit in the predetermined header space? Now you get to decide how much header image you want, without having to touch any code.
Awesome, right? And it’s easy to get it to work with your theme.