Amazon has (at least) three different categories of streaming movie availability:
free for Prime members cost unavailable
Movies can move between these categories (e.g., Serpico was free on Jun 29th, 2013, but was unavailable as of Jun 30th, 2013, while Best in Show was free on Jun 29th, 2013, but costs as of Jun 30th, 2013, costs $2.99).
Amazon does a pretty good job of letting you know what movies have recently moved into the free category via their Recently Added category.
What I haven't found, that would be really useful, is information on upcoming category changes (e.g., it would have been really useful -- to know before Jun 29th, 2013 -- that Serpico wasn't just going from the free-to-cost category, but was outright becoming unavailable).
Is there an availability schedule for Amazon Prime Instant Video that shows upcoming category (i.e. free, cost, unavailable) changes?
[Originally asked Jun 30 - https://movies.stackexchange.com/questions/12287/is-there-an-availability-schedule-for-amazon-prime-instant-video. Deleted July 26th by TylerShads with no explanation why it was deleted.
Asked again July 30 - https://movies.stackexchange.com/questions/12859/is-there-an-availability-schedule-for-amazon-prime-instant-video. Deleted same day, again by TylerShads with the explanation, "And I'm deleting this again because this type of question has to do with distribution, which is off-topic for this site, and this question is better suited for Amazon. – TylerShads". This despite another "distribution" question being asked less than 24 hours prior to my original question, a question that hasn't been deleted - Why can't movies be released in homes? (edited to add link). And despite the fact that non-providers have been known to provide the service I'm an inquiring about - http://www.engadget.com/2013/05/14/netflix-watch-instantly-expiring-dates-api-removed-streampocalypse/ . In the cited case, there was a provider API, that has subsequently been removed, but the fact remains that non-providers were precisely the organizations to provide the service which I'm inquiring about.]