5 is tough. I don't think you are ever going to get to 'keep' the shows. Play them on different devices? Sure, with applications that is totally doable. Watch them as many times as your bandwidth allows and as long as you keep paying the subscription? Sure, stream away. But keep them? No. Content creators got bills to pay too.
i think it will get to the point where everything is just streamed, or you could download DRM free movies. they did it with music, they should do it with movies. theres so many devices out there, so many thin clients that just cannot play DRM content.
so instead of movie companies making money off selling movies these devices can play, they force people to get movies in other formats that the clients can play (eg downloading a mkv torrent)
it will be interesting to see how ubuntu tv sells/rents movies when that comes out