This is an extremely smart play by Disney.

Everyone realizes that content is king, which is why Amazon and Netflix are busy making their own content. Disney already has the content. This is them building the distribution network. People complaining about how this will lead to each studio having their own service, are missing that this is where things are going anyway, just with Netflix and Amazon playing the role of studio.

This isn't really out of character for Disney anyway. They really like vertical integration (they own their own film distributor, for example).