Historically Steve has been anti-subscription services, at least for music. And Yahoo's departure from subscription music in the last couple days probably enforces that might have been the right choice.
But for movies, I think the argument for subscription services is much stronger. Clearly Netflix (my service of choice) and Blockbuster have proven there's a major market for subscription movie rentals. And now that Netflix has unlimited streaming, if their catalog grows it'll be a major threat to iTunes movie rentals. Netflix's 6,000 movie selection for streaming sounds impressive until you compare it to their selection of 90,000 physical DVDs. Just makes me wonder how many movies would actually be available for an Apple subscription service. And at least for my use of Netflix (and I think I'm not alone in this), there would need to be TV show rentals too for me to ditch Netflix, since that's easily 50-80% of my rentals at any time. And somehow I don't see Apple or production companies giving up their $2/episode pricing for TV shows in exchange for free streaming of their shows any time soon.
So I don't think you're totally off base to hope for it, though I'm not sure if Apple is pursuing it or if it'd be everything we'd hope for even if it does happen.