I don't want Chrome OS and Android to merge, I want something else
Chrome OS is the future, but the future isn't here for mobile devices.
HTML5 apps aren't that good on mobile devices (Hey Facebook!) and Android apps will be touch based while the web isn't (yet). So a merger isn't really possible.
But, why not have both?
You put your tablet into the dock (We should see this first on Nexus devices so advice to Google: Make the dock cheap or sell it with it) or couple it to a screen via miracast.
The screen of the tablet should display a keyboard and a square for a "touchpad" so you can control the other screen with it.