Well, Blockbuster is losing money on subs who frequently make the instore exchanges. And as I understand it there is no "grandfathering". They are doing some kind of case by case evaluation.

TWC does not want anyone else renting the movies to justify the HUGE cash guarentees that blockbuster is paying them for "exclusivity". If TWC does not want to distrubute their titles to video stores they may be fine to do that, if netflix wants to run down to Target and buy a ton of copies of "Bobby" or something and rent those out they are obviously able to do that under "first sale" but that may prove to be cost prohibitive.