I think it's because there was a sentiment among some reviewers (Anandtech/The Verge) that in spite of the remainder of Windows 8's flaws, there was actually some merit in having the touchscreen as an additional input type, to the extent that they found themselves touching non-touch laptops even after the review period ended and the units were sent back.
I think what they're going for is to continue to have ChromeOS be primarily mouse/keyboard based, but to support the new hybrid form factor since as an interaction model it seems to have some promise.
As for the distinction between ChromeOS VS Chrome on Android, I think the key is in their focus. ChromeOS is a device targetted at the Desktop Web, whereas Chrome on Android is targetted at the Mobile Web. Google wish to be competitive in both so maintain two different teams/products attuned to each so there's no conflict of interest with regard to resources (Innovators Dilemma).
tl;dr Android is a mobile OS, attuned to that market whereas ChromeOS is a Desktop OS, attuned to the Desktop Web. Google needs a stake in both since those are the two main channels that Google depends on for its continued existence.
I think what they're going for is to continue to have ChromeOS be primarily mouse/keyboard based, but to support the new hybrid form factor since as an interaction model it seems to have some promise.
As for the distinction between ChromeOS VS Chrome on Android, I think the key is in their focus. ChromeOS is a device targetted at the Desktop Web, whereas Chrome on Android is targetted at the Mobile Web. Google wish to be competitive in both so maintain two different teams/products attuned to each so there's no conflict of interest with regard to resources (Innovators Dilemma).
tl;dr Android is a mobile OS, attuned to that market whereas ChromeOS is a Desktop OS, attuned to the Desktop Web. Google needs a stake in both since those are the two main channels that Google depends on for its continued existence.