Originally Posted by sonic
...this will increase size and not sound quality.
First this isn't entirely true. Sound quality is much better at 24bit vs. 16 bit. Furthermore, recording software is much different than it used to be. Originally, some low-level 'noise' was added to the recording to help record low-level signals (this is called dither). It sounds dumb but it worked. Modern recording software doesn't need this anymore and it is rarely used. Mastering engineers don't do noise reduction. They apply fades in/out on the song files and base the fade on the noise floor and how the song starts/stops.
The main problem is that this is already available and nobody pays for it. SACD and DVD-A are both higher resolution media that have been around for over 10 years. The cost of the discs and the equipment to playback is much higher than cd's. Most people don't hear the difference anyway so this will never become maintstream. In fact, most people are going backwards in quality for the sake of convenience with MP3's.
Until storage capacity and streaming rates are MUCH higher than what is currently available, we won't see anything new from the record companies (especially if it doesn't make them a huge sum of money).