re: FLAC encoding
Writing to flash media also takes energy. Sony's D100 pages brag about MP3 battery life on their unit. To me that suggests that despite the heavy processing to encode to MP3, they are already making battery savings by writing far less data to the flash chips versus the raw data being dumped onto them.
I don't see why FLAC can't be done similarly (eventually), since encoding to FLAC doesn't require any of the heavy-processing psycoacoustics algorithms, right?
Writing far less data will mean power savings when writing to flash, which could offset some of the processing power consumption...I don't know. Sony had no problem with battery life when they were making MiniDisc. ATRAC was implemented really well and it meant less motor spin time and effective buffering. Anyway, MP3 has had a long time to get to the stage it has now (as far as efficient encoding implementations are concerned), so it may take a while with FLAC too, but to be honest I don't think enough demand is there among the population, sadly. Because I think it could be done easily if the will was there.
One thing I do know is that the HD camcorder I bought recently does really well with battery life, despite massive number-crunching recording to AVCHD or MP4. In comparison to this complexity, FLAC encoding would (should) be far easier. FLAC's problem is that it's not integrated in any major consumer standards from any of the Big Companies, so there must be far less will to go there except in specialist devices such as this, which finally get some playback love.
We don't see FLAC implemented in Blu-ray standards. Not in CD. Not in DVD. Not in many electronics used at home or portably. So there's probably not much incentive to develop (and spend money on) an encoder. Anyway, I'm happy that playback is there. This is how it started for MP3 too.