This is a digital disk (and solid state) media player.
And despite the title of the post, it is not in direct competition with Blu-Ray. It's not a consumer format. It's not even a fancy disk format. It's just a solution to produce a compact high-definition digital-cinema player.
RedRay will do something that BluRay cannot. It will play movies at 4K from a box about the same size as a DVD drive - to a suitably equipped 4K digital projector.
By way of comparison. BluRay's image size is 1920 x 1080 pixels.
"2K" resolution is a bit higher than that. (Full Aperture Native 2K is defined as 2048x1556) Most experts think that a good cinema resolution is typically around 2K.
4K has twice that linear resolution. So we are talking about an image size of 12 mega-pixels versus BluRay's 2 mega-pixel image.
So a sensible question is: What's coming off the disk? RedRay uses a codec which has a high compression ratio. And apparently very few compression artifacts. In a recent demo. Red showed an audience a 4K showreel - and then revealed that the data-stream was just 10 megabits. Not much more that a standard def MPEG2 DVD. Although it can use much higher bit rates.
I am not suggesting this is a some kind of nail in BluRay's coffin ... but does suggest that better technology is arriving all the time. So it's going to be tough to stick to a standard and expect it to last for 10 or 20 years.