Yeah, mostly on iMacs and the laptops.
I don't think it's a full hardware calibration, but contrast, brightness (funny how brightness really means blacklevel other way with video displays, whereas contrast means brightness, they "contrast" as used in computer displays have no equivalent in video displays), colortemps etc. And I don't suppose it's able to move the primaries around and their luminance levels. It still needs to do a software LUT AFAIK. I'm not very familiar with macs though, so please do correct me.
Some Windows machines also use hardware when adjusting the RGB controls, but you really have no way of knowing if it's done in hardware or software. In these cases I usually just go for software. There's always some higher dE at the lowest and highest end, but that's expected.