Could all of Google's web applications be getting an interface refresh that would make them more like Google Wave? Screenshots published by Engadget appear to suggest that may be that case, though it's not clear how far the changes are away.
In Wave, it's possible to collapse and expand modules like the navigation bar, contacts window, inbox or individual Waves, as well as minimizing them to the top of the screen to appear as a drop-down menu. The screenshots appear to depict the same setup applied to Gmail, and Google News.
Apparently "the goal is to provide a consistent experience throughout all Google Apps and blur the line between the browser and the website (e.g. drag and drop, right-click, etc)". That could imply a similar interface for Chrome OS too, as well as future Google products.
We'll bring you more on this when we hear it.