Improvement of Ribbon bar collapse behavior
Collapsing the ribbon bar from the right hand side to the left is not always preferred, despite the design goal being to put less frequently used items on the right. The fix: when the ribbon is wider than the current window, use small scroll buttons to shift the "active" portion of the ribbon left or right (collapsing the ribbon on the other side).
This would make work-flows which use rely on either side easier without sacrificing real estate or functionality, and make the ribbon more extensible without changing its essential nature or look and feel.
Alternative: add another small button (similar to the dialog launcher) which can collapse individual groups selectively, allowing the user to choose which groups remain active, and keeping the existing collapse behavior for resize events.