If you have one file per window off, you will be able to use next-buffer to switch buffers within a floating window.
The exact features for floating edit windows for v18 is not known.
Here's what we think we can get into the first version of floating windows:
* Ability to split windows inside a floating window with a similar document tab context menu as edit windows docked inside the MDI frame.
* Each floating window will have a command line and status line. We haven't decided what that status line will have but we expect it to at least have a line and column display. Hopefully a lot more.
* Ability to maximize and restore floating windows.
These won't make the first revision of floating windows:
* Ability to dock toolbars and any sort of ability to remember what toolbars were docked.
* Ability to dock tool windows and any sort of ability to remember what tool windows were docked.
* Fullscreen mode for floating windows. If we support docking tool windows, this could be handy.
There are some complexities having to do with handling duplicate tool bars and tool windows which make this difficult (but it's still doable). We might have to limit which tool bars/tool windows can be duplicated.
Note: There will only be one menu bar which is on the MDI frame. Floating windows will not have a menu bar. I don't think this will ever change but it might be nice to have.
Under Mac, Windows, and Ubuntu (with the Unity desktop), you will be able to invoke operations from the MDI menu which will operate on the active floating edit window. Unfortunately, there will be issues with Unix window managers (non-Ubuntu Unity platforms). With other Unix windows managers, clicking on the MDI menu bar will cause the MDI frame to come to the front and there is no work around for this. Unix window managers are very crude.
We expect the Windows version to support clicking on docked (and possibly floating) tool bar buttons and having them operate on the current floating edit window. I don't think we can make this work for other platforms though.
I hope everyone finds this new Document tab interface cool. I know I'm loving it!