Chrome OS is Google's baby so a Chrome Tablet is very likely. Android is the result of a more aggressive gambit from Google; as part of a short term strategy to aggressively compete against Apple & Microsoft; to maximize momentum and leverage the 'open source' buzzword.
Long term, it won't be surprising to see Google transition it's efforts to Chrome exclusively. Eventually dropping Android support entirely (but they'll do it with nice PR so it looks like they just "gave" it to the open source community).
I think this makes a lot of sense even though it is kind of crazy. Chrome really seems to represent Google's philosophy for development more than Android does. Both in that it is developed more in the open and that it is all about web development for everything. I know that Eric Schmidt has talked for years about having everything come through the browser, Chrome is Google's platform for that vision.
I am not sure we will. On a question in a video I once saw, it was asked from Eric Schmidt how Google sees the difference between Android and Chrome OS. And his answer was that they see Android for the kind of tasks that don't need a keyboard, and Chrome OS more for devices that have keybord ("traditional" computing tasks). I don't remember the actual wording, but something to that effect.
This seems unlikely given that Google Apps, and the web in general, isn't built with touch in mind. They could make that change to the properties that they own but when the whole platform rests on web content, the lack of interfaces built for touch hurts the user experience.
I'd rather like to see Chrome and its features getting more tightly integrated with Android. If one could use the Chrome Web Store from an Android tablet, there wouldn't be much left that Chrome OS does better.
Chrome and Android are different teams. I think it's more likely for Google to sell both Chrome OS and Android tablets than for Android tablets to run Chrome.
Long term, it won't be surprising to see Google transition it's efforts to Chrome exclusively. Eventually dropping Android support entirely (but they'll do it with nice PR so it looks like they just "gave" it to the open source community).