Redditor /u/-nbsp- has pinned down a file from the Chromium gerrit that lists an as yet to be released Chrome OS device with a 4K display.
The device is listed with a 3840 x 2160 panel and is able to boot recovery images from a USB drive, but does not feature a microSD card.
It was about a month ago when Chrome Unboxed caught onto a repository thread mentioning “atlas” for the first time in reference to “eve,” what we know now as the Pixelbook.
WIP: atlas: add board support, posing as an eve
this takes the atlas EC code and drops it on top of the eve code so we can boot up atlas with an eve build.
It’s believed that since code was cloned from the Pixelbook that “atlas” will run an Intel 7th-gen “Kaby Lake” Core processor. Besides that, nothing else is known about the device at this point.