The Wall Street Journal suggests that Apple and major film studios are currently negotiating for the right to offer streaming movies from the iTunes Store. According to "people familiar with the matter," the deal would allow users to stream movies they've bought from iTunes to portable devices like iPhones and iPads without having to use a Mac or PC to transfer them over first.
This is broadly similar to the deals already in place for music via iTunes Match, which allows multiple downloads of purchased music to any device associated with a user's iTunes account. While Apple says iTunes Match isn't technically music streaming, this new rumored movie service would be, and it may build off of tech and knowledge Apple gained when it acquired Lala.
Anyone who buys movies on Blu-ray or DVD is already familiar with how much of a pain it is to get those purchased films onto an iOS device. While you can always rip the DVD and encode it in a compatible format using third-party tools like Handbrake, customers and iOS device users need a better solution than that. The studios have already achieved limited success with their own UltraViolet program, which allows access to films online for customers who purchased a DVD or Blu-ray. The WSJ correctly notes that movies purchased from the iTunes Store aren't compatible with UltraViolet, however, so it's not a universal solution.