Understood - but let me clarify what I meant by realtime. I don't mean "live", I agree that's not relevant.
Introducing a delay of even up to 1 min as you suggest doesn't compensate and allow for less powerful/cheaper hardware to be used. By realtime, I mean the hardware needs to be able to process the video stream at the same rate it is coming in - in other words, not take an existing file and convert it, then play it. Because TV is "realtime" in this sense, if the hardware is not powerful enough, even a delay(buffer, really) of 1 min will eventually run out, because the hardware will progressively get further and further behind .... then black screen! So it is the nature of TV not having a set "end point" like a file does that prevents you from using the lower powered hardware.
If you used that lower powered hardware against a file, that would be fine, you would just have to wait loner before you could begin watching the content. But that doesn't logically have an analogy in a realtime stream. No matter how long you waited before beginning the content, eventually the content would catch up with the hardware and the stream would stop. So the hardware needs to be able to encode at at least 1.5Gb/s.
Moreover - even if introducing a delay (buffer period) of 1 min did fix this issue of lower powered hardware, this would happen every time you changed channel - not many people would be prepared to wait 1 min per "flip" in channel surfing!
I don't disagree that there are encoders (decoders are always cheap because they have far less to do) that can do realtime streams, possibly cost effectively. I guess this goes back to my original point - these algorithms are necessarily adaptive. The higher quality you want out, the more time they take to do it (at the same price point, roughly!) - once you configure it for a level of compression quality that gets to less than 25/30/50/60 frames per second, it can no longer be used for this job, effectively setting an upper limit on the quality of the compression for a given piece of hardware (and therefore price).
Remember the first DVD recorders? Their video quality was appaling, even though some of them used MPEG2 - those encoders for CE equipment were VERY expensive initially, and so this set an effective upper limit on quality compared with what consumers were prepared to pay. As volumes and technologies progressed, they were able to achieve much higher encoded bitrates at lower costs, so quality went up. Same principle - if there is the demand for this then I agree that 2009 will be interesting, but I think that demand will only come from HDDVD and BluRay recorders, not from wireless HDMI cable replacements... much higher volume...