I have to admit that I have used and enjoyed the Xbox 360 Live movie rentals on a number of occasions, and enjoyed the service, my only issue being the download time to get the film.
When renting a standard def movie the download time isn't all that bad, but download a HD movie and forget it, especially over wireless, I'm talking days, not hours, and that's only 720p
In their E3 conference yesterday Microsoft announced that they would be changing the system soon to have 1080p high def movies, not you may be thing that would take weeks to download, but no, Microsoft are going to off instantly available movies.
No work yet on pricing or exact availability, or if this will be good over wireless as I'm sure many users will have on their Xbox, but this could be the start of something good for movie rentals, this country needs it with the lack of a good rental service available.