Well, that's just it - HTML5 video will allow Apple to make whatever optimizations necessary to keep power consumption to a minimum.

If video is wrapped inside an opaque Flash container, a huge chunk of Apple's user experience is now squarely in Adobe's hands; this isn't confidence-inspiring given the general stability and performance of the current Mac Flash app.

There is quite a big difference here.

Adobe allows for interaction with the video. Apple QT is just that... video.

Not when you have a hardware H264 chip.