Finally another studio jumping in. I'd love to see Warner Bros., Universal and Columbia come into the mix. Unfortunately, as another has hinted at, only the US store gets this sort of content. The rest of the world is very much in the dark with regards to iTunes' growing video content. My gf in Montreal can't even download her favorite episodes of Lost. Fortunately, the US is not a little place, so will still be a healthy stream of income for iTunes' video store. I'm pretty sure there's plenty of legalities that I haven't thought of with regards to launching a global video store.
I think that the pricing for some of the movies is atrocious. Some of the Disney flicks that have been around for over a decade now are way overpriced. I could go out right now and get a DVD for nearly half of what some of those videos ask for, and at the same time I'm just as willing to pay more than what iTunes charges for some of them for the unrestricted, rippable DVD, which doesn't have the 5 computer per account rule applied when converted into mpeg-4/H.264 format.
If you ask me, an eventual iTunes video rental service would really boost support for the ATV I believe. It would have the same perceived value as renting a physical DVD and at the same time means a far smaller cost than the likes of Blockbuster and local video rental places, not to mention the convenience for anyone with a high speed connection. I'd rent a lot of movies if iTunes had this service, even though I'd still buy the DVD later on (if I think it's worth purchasing).
As for the whole iTunes infrastructure itself, I'm wondering how this all goes considering the growing animosity the European governments have against the closed iPod+iTunes ecosystem. For people that have Macs, such as myself, this isn't a really big deal since no matter what Macs will have few mp3 players supported, but for the majority that uses iTunes on Windows this is a very big deal. I'm wondering what will happen if and when iTunes opens up to other players, or if the DRM-wrapped media will be set free and allowed on non-Apple hardware. As nice as the ATV concept and iPods are, people want more choices, which they feel Apple may be locking out. While I love my iPod, I sort of agree with them. The more and more content is released in the store, the more people will be looking at other hardware wondering when the hell Apple will let them just buy the music and movies and play it elsewhere.
I'm sure few look at the Zune Marketplace with this sort of critical eye because it's US only. If and when it goes Global, then that's sure to make things interesting.