There are some shots in ESB:R that have taken hours to encode just over a seconds worth of film @720p with all the layers & effects used and that is on a 6 core 4.5ghz i7 machine. Can you imagine the encode time when working at 1080p for those shots?

The blu-rays certainly weren't "around the corner" when i did ANH. They didn't come out for almost another 4 years AFTER i had completed ep4. Even the HDTV captures didn't come out until i was most of the way through the edit.

Even though i will be redoing EP4 in HD, i see no reason to have to go back and redo everything just because a 4k version may or may not be released. If i had that sort of mindset i would be waiting forever just to begin work on the films. I would be celebrating the release of the final film alongside my centenary birthday ;)