We don't know much about the future flagship Chromebook Google has in the works; it's codenamed Link and seems to be a high-end device, at least compared to the existing Chromebooks. We know it's coming, but that's about it.
Still, there are some pretty strong hints for at least some of its features; the screen seems to be getting the center stage. Rumors say that it will be a Retina-class display with touch input.
What is clear though is that Google is both working on a high DPI interface for Chrome and is implementing some more touch friendly UI elements.
Chrome already has a high DPI UI for Retina display Macs, but the feature is now making its way to Chrome OS. In the Chrome Flags section you'll notice a new experiment labeled "Force high DPI mode" only available for Chrome OS.
Since all Chromebooks come with a standard and definitely not Retina display resolution, the feature would be rather pointless unless a device capable of such a resolution was in the works.
The only other possible application for this feature in Chrome OS is in Chromeboxes, which have to be paired up with an external monitor. Likewise, you can hook up an external display to any Chromebook.
Apart from the high resolution, Google is also working on making Chrome more touch-friendly. The menus in Chrome 26 are already significantly larger than they were before, on Windows at least.
The change was made for all devices, with touch input or not, but it's clear that Google wanted to make the menus easier to use with a touch display.
Again, this doesn't mean a touch-input Chromebook is in the works; after all, plenty of new Windows 8 laptops come with a touch input display. But there are too many coincidences, too much smoke for no fire.