With respect to particular movies that were rentable and now were not (I also would point out that certain titles have disappeared in the last couple of weeks), I think it's safe to say that we just don't know the answer. I doubt it's what Apple wants, because their strategy otherwise has been to try to add as many titles as possible, both for rental and purchase. However, we also know that the folks at Apple are tough negotiators with the studios when it comes to terms. My guess is that one or more studios sought a bigger piece of the pie or some other term that Apple found acceptable and Apple refused to make the deal.
We all want the same thing -- a huge library where every title can be rented or, for greater cost, purchased. We all want rental terms that meet or exceed what we could get from, e.g., Blockbuster. (I agree completely as far as the 24-hour limit, which I know Apple doesn't like. My wife *always* falls asleep in the middle of movies and wants to finish the next day, so ATV rentals currently are a no-go for us.) Unfortunately, we currently have to wait until Apple (or someone else) gets enough power to dictate terms to the studios, or until the studios start to realize that the download market is worth really competing in. I'm guessing that we're a couple of years away from the point that all of the relevant players "get it."
We all want the same thing -- a huge library where every title can be rented or, for greater cost, purchased. We all want rental terms that meet or exceed what we could get from, e.g., Blockbuster. (I agree completely as far as the 24-hour limit, which I know Apple doesn't like. My wife *always* falls asleep in the middle of movies and wants to finish the next day, so ATV rentals currently are a no-go for us.) Unfortunately, we currently have to wait until Apple (or someone else) gets enough power to dictate terms to the studios, or until the studios start to realize that the download market is worth really competing in. I'm guessing that we're a couple of years away from the point that all of the relevant players "get it."