Feature: Front Row is updated to work just like Apple TV, but on your computer.
How it works: To tell the truth, I kind of liked the spinning icons of Front Row (and so did this kitten), but the Apple TV interface is nice, too. You can play all of your content (and even content streaming from other computers) straight through the interface, and obviously, DVDs, Podcasts, and Photos are all included in there as well. It's all built right in to every copy of Leopard, ready to operate from across the room with the still awesome Apple Remote.
Who will use it: Anyone watching movies or playing media from a distance on their Mac. And especially those of us planning on picking up a mini-- hook up a video out to the TV, and you've now got an Apple TV that does so, so much more.