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.
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).