This is one of the best tech moves the company has made under Iger, not that that is saying much. It's infrastructure that, if managed and developed well by TWDC and its partner in the MLB, can run much more than an HBO Now version of ESPN.
MLBAM's backend already runs many of Disney's TV Anywhere apps like WATCH Disney Channel, Disney XD, Disney Junior, etc.
Just to get a feeling from the group, should Disney consider turning the ESPN and Disney blocks of channels into Premium Cable like packages à la HBO?