In Blender 2.8, we've moved all the tool settings to the top bar. This allows users to work in full screen mode, and still have access to all relevant tool settings.
In order to fit everything, for some tools we use popovers to display panels with related settings. While this has advantages in many common cases, we still want to add the ability for users to have persistent access to tool settings.
We want to do this by adding a new Tool Settings Editor.
Technical Note: Technically it's part of the Properties Editor, but will be exposed in the UI as a separate 'fake' Editor, in the Editor dropdown
Here's an example of how this will work:
As you can see, the Tool Settings Editor shows the exact same settings as the top bar, but expanded into panels.
The Tool Settings Editor will work for all tools in all modes.
We also want to include a 'Tweak' panel here, with persistent access to redo-settings.