Having worked many years in the film and video production world, I look at this much differently. Unlike the 3d novelty, the quest for higher quality acquisition in the industry addresses the primary requirement for content. Most film libraries have been digitally archived by the studios at much higher raw resolutions and this content is readily available for immediate release. Many production companies are already acquiring in UHD. I see network UHD content availability in prime time and sports to be very probable in the next few years. Agreed that there isn't much compelling reason to or financial incentive to produce local content in 4k.
Likely that the traditional distribution methods will be used for getting the content positioned for consumer consumption. I am sure that both satellite, fiber and Internet will all play a role. The final mile to deliver the UHD content to the viewer is the main issue. Likely that local broadcasters are not in a financial position to upgrade their signal path for complete transition, but to stay relevant, they will find a way to meet the technical hurdles to be part of the evolving entertainment delivery industry. I believe that mobile terrestrial devices will play an ever increasing role in addressing the final mile.