Apple's latest bulletin via the iPhone Developer News feed highlight how we really might see 3G connected SlingPlayer -- and even Hulu -- on the iPhone, iPod touch, and iPad without melting the cell towers, courtesy of HTTP Live Streaming:
HTTP Live Streaming provides a state-of-the-art standards-based solution for streaming video over wireless networks. A key benefit of HTTP Live Streaming is the ability to dynamically adjust to varying network bandwidth conditions. It can store multiple video clips of different quality on a server, and then deliver the one that matches what the customer is capable of viewing on the network they are currently accessing.
Your application must use the HTTP Live Streaming protocol if it uses the cellular network to deliver video for any stream with a duration of 10 minutes or more. In addition, applications using HTTP Live Streaming over the cellular network must include a low quality stream of no more than 64 Kbps for your app to resort to when network conditions demand it.
The key here is that HTTP Live Streaming can dynamically increase or decrease video quality as you move from beefy Wi-Fi to 3G, standard or starved. Do we mind getting worse-looking video when the network is being strained? Years of putting up with blocky YouTube cat-on-piano videos likely points to "no"...