Blockbuster seems to be getting on board now with their own kiosks popping up. Ultimately, however, the future will be fee-based digital downloads.
Our daughter pointed out something the other day that I hadn't considered. Since you can return a movie to any other Redbox, you could use the service while traveling. If you have a laptop, or a DVD player in your vehicle, it makes for more interesting travel for the kids, or even yourself, when you get to your hotel on the road, and aren't sure about TV reception. You could scout out Redbox locations before your trip, or look them up online along the way, so you'll know where to find one to pick up, and then later, to return it.
I'd seen this with books at truckstops; pick it up at one, and drop it off somewhere along the way.