In some ways, this is Apple pushing things forward... but in other ways, it's just them catching up. Until this update, there was no way to get 10-bit displays working with Apple products at all, even third-party monitors that were 10-bit capable. The OS simply wouldn't support 10-bit display. I know you could get it in Windows, and almost certainly in Linux with the correct voodoo.

My post guys wanted to stay on the Mac platform, so we dealt with 8-bit displays (color wasn't a huge part of our workflow -- but 10 bit would've been nice). But it was one of those head-smacking moments for a platform that was supposedly media-friendly.

Note, there's some confusion in the comments so far -- 10 bit is a professional display, and is extremely uncommon. Pro cameras and software can usually handle higher bit depths -- 16 for DSLRs, 10-12+ for pro video cameras -- but you're probably not seeing it unless you've carefully set up your computer. Those bits are still useful: they're the raw material for generating your 8-bit final image, so you don't get banding when adjusting color or exposure. And they're essential for containing a wider range of possible values, letting pro cameras represent a wider dynamic range than is possible in 8 bit systems.

And 8 bits is more typical -- it's literally baked into many file formats, like JPEG. Some crappy screens on consumer electronics can't even represent the full 8 bits per channel; 6 bits + dithering is sadly really common, even in screens that advertise themselves as 8/24-bit. Also, color depth can be reported both in bits-per-channel and total bit depth; a 10 bit-per-channel display is 30 bits of color information per RGB pixel, 10 each for red, green, and blue.

(Some of the confusion is probably intentional; I had a hardware partner brag about their '15 bit display,' which sounded very weird to me... until I realized it was really 5 bits per channel, which is roughly bad-ATM-screen quality.)