The SC ruled that the number of antennas or where they're located is not the heart of the issue. Aereo effectively supplied a data stream with broadcast content to subscribers (just like a cable tv company) without licensing the right to supply that content. The issue is commercial rights, not technological means. If you personally lease space for an antenna, and engineer a means to get it to your TV to watch, that's ok. If you sell access to the content stream, you are a cable TV company and have to pay redistribution license for the content.
Aereo effectively supplied a data stream with broadcast content to subscribers (just like a cable tv company) without licensing the right to supply that content.
This is also what ESB would be doing by letting people rent antennas and streaming servers.
ESB would be renting antennas, and then what you do with them is your own business.
Aereo is selling streaming TV service that just happens to use antennas in the backend.
You might say, it's all the same in the end from a technical point of view. And you're right, but the law doesn't care about the technical point of view. From the legal point of view, Aereo is selling TV streaming, and must comply with laws for TV streaming.
I think the service itself would need to be changed as well. I think if they explicitly rented antennas and that was reflected in both their marketing and their actual service (e.g. providing a raw bitstream for a user-selected frequency rather than providing a video stream for a user-selected TV channel) then they'd be alright. This is just what I've been able to understand of the situation and I'm not an expert and could be terribly, terribly wrong, of course.
