"Fiber to the home" is an extremely ambiguous way of putting it. Copper can carry 10Gbps, or more economically 1 Gbps. Fiber is required in densely populated areas, where you and all the people around you share a good uplink.
Anyway, isn't "fiber" in a consumer setting related to speeds closer to 100mbps? If they can't make this service work on 10mbps, they'll alienate more than half their costumers. You seem to forget that this is essentially nothing more than Netflix. It's just a stream of video of your game happening at a remote location. So, interactive Netflix, I guess. The only data upload that happens is your button presses. Also, I know the entire bandwidth capacity of Netflix in my country - there is no way you can easily distribute content to a lot of players at even at 20 mpbs. Netflix' HD streaming is ~6mbps. I think it'll be around there.