At the end of last year Sony announced a new audio disc, the Blu-Spec CD. This is an interesting idea - they’re using a blue laser (the same process as Blu-Ray Disc) to burn a standard Red Book Audio CD.
To be clear, this is not a high-res audio disc. It’s a standard Red Book CD, playable by all CD players. The difference is in the creation process.
The advantage is that the shorter wavelength of the blue laser allows for more precision in the pitting of the disc. This should result in fewer errors on playback when read by a standard CD player with a red laser. This raises an interesting question about the audibility of errors in CD playback - what do they sound like, and how well does error-correction work?