If you doubt the efficacy of the new Pearl e-ink displays, take a look at these comparison photos. It looks like a pretty serious difference to me, although we’re still talking dark grey on light grey as opposed to black and white. I didn’t alter the pictures other than cropping them; take this comparison with a grain of salt, as it’s not exactly scientific.
I’d like to see these things under the microscope, too; I’d like to see what increased contrast looks like on a blob-by-blob level.