Prediction: The much-anticipated convergence of Android and Chrome is near. These new Chrome apps are the programming model for the upcoming native Android webapps The next milestone I expect to see is V8 added alongside Dalvik as a first-class runtime for Android. Maybe in Android KitKat?
What exactly are you expecting to get from the mythical "ChromeOS and Android merger", when you already have Chrome for Android?
The only major things I see ChromeOS has over Chrome for Android is the security model, which will be impossible in Android, since you need native apps, too, while ChromeOS will only ever work with "web apps". Changing that could mean its security model will suffer.
And the second one is the upgrade process, for all Chromebooks, coming straight from Google, every few weeks. That's ideal, but I doubt we'll see anything like that for Android even this decade.