There's an article at MacRumors from a guy in the media who took some pics in the demo area, and he says, depending on the lighting, Midnight can look like a mix of navy blue and space grey.
Hmmm.
The pic in the article, it looks completely black to me (or super, super dark grey; I see no blueish cast in that photo).
I've seen where others have described it as "matte black".
I think Gurman mentioning "blue" in his report 2-3 days before the keynote has everyone seeing blue, when he himself probably saw leaked PR pics, which do look a tad blue-ish.
This is going to be the tech version of that whole "what color is this dress?" thing from a few years back, with half the population seeing one color and the other half seeing another.
