I am probably going to grab TDKR on iTunes, having somehow missed its theatrical run when I was in the USA.
I could never figure out why people would buy movies or TV shows from iTunes until I got an AppleTV unit. Now I'm able to watch my stuff on my iPhone, iPad, TV, or computer whenever and wherever I want, and Apple isn't giving me any shit about my physical location, unlike Hulu, Amazon Prime Instant Video (including shows I purchased, not just their free streaming stuff!), and Zune/Microsoft Xbox Video.