Right now there's a deal in place that makes the folks at Redbox and Netflix wait until 28 days past the release of a DVD or Blu-ray to start renting it out to people. This is pretty standard with all studios and seems to be working out well. Warner Bros. doesn't see it that way though. Rumor has it they'll be expanding that further - a lot further.
Warners is reportedly going to be asking for a 90 day delay, meaning that if you want to watch a newly released Blu-ray you'll have to buy it, go to a brick and mortar rental store or wait three months. Warners is hoping that this longer wait time will help them sell more DVDs and Blu-rays, but it's a bit of a gamble, since Redbox and Netflix will certainly be buying fewer discs. The delay is reportedly starting on November 1st.