I think is the death knell for ChromeOS. Android browser has always sucked, it was the primary reason I haven't bought an Android device. Google had the resources to make Chrome on Android a long time ago, so I presume they were dragging their feet in a "wait and see" approach for whether ChromeOS had any chance on its own.
First off, this took so long because Chrome was built using a "normal" devel framework (gcc, make, etc) with a few added tools (repo, gyp). The UX for Chrome is provided via OS-specific graphical APIs, like X.org, Cocoa, and Win32.
Android uses a Java framework, which in turn contains the code that manages all rendering and UX, so not only did Chrome UX needed to be ported to Android's graphical API, but the entire build environment needed to be JDK compatible.
I agree the Android browser is laughable compared to Chrome, and Chrome on Android is the future, but there were so many developmental problems that needed to be solved first before one could stick to the other.
Regarding your ChromeOS comment, this has nothing to do with that as ChromeOS is designed to solve an entirely different problem. Many power-users (developers, technology bloggers, etc) seem to have a hate-on for ChromeOS because they're afraid it'll kill their venerable laptop. That will never happen. :)
ChromeOS is designed to kill those netbooks and laptops where common-users (my wife, for example) only use them for browsing gmail, facebook, and a few forums. 95% of what these users do are web based, barring a few native apps, of which NaCL and other HTML5 technologies are aiming to solve.
