With the release of the second-generation Apple TV, support for iTunes Extras was lost and became only available from iTunes running on a computer. Now Apple is bringing iTunes Extras back in from the cold, reinstating it to the Apple TV as of today. It's only available on the second and third-generation Apple TV, not the first.

If you fire up the Apple TV and open the Movies tab you'll see an iTunes Extras option in the scrolling options across the top. Click here and you'll find a list of 50 movies which include iTunes Extras content. Browsing in iTunes on a computer, there seems to be more than 100 movies supported.

Movies that support iTunes Extras can include behind-the-scenes video content, directors commentary, short films and high-resolution photo galleries of storyboards or concept drawings. Because it's all hosted online, Apple can add extra content over time – although the same applies to Blu-ray extras and not much came of that.

Thankfully if you already own one of the iTunes Extras movies you'll get access to the extra content, but the big catch is that iTunes Extras is now only available for the HD version of movies. The movies cost more and can put a rather big dent in your download limit.

If you're on a slow internet connection you might need to wait an hour before you can press play on a HD movie. At this point you might decide that iTunes Extras is more trouble than it's worth until the NBN arrives in your street in one form or another. As with many tech companies, Apple's decision to limit iTunes Extras to HD movies feels like a US-centric decision which doesn't take into account that many people don't have the fast download speeds and uncapped download limits most Americans enjoy at home. The fact that it leaves owners of first-gen Apple TVs in the lurch also sucks.