>>>> It's not perhaps the solution that would suit everyone, but I'd bet 
>>>> some users will prefer that to the way they are currently displayed. 
>>>> A third option would indeed be a kind of pop-up buffer.  And there 
>>>> are probably other options.
>>> 
>>> Popup buffer and popup frame (perhaps a child frame?) are IMO the only 
>>> viable alternatives that are worth having in Emacs.
>> 
>> A popup frame is not an option for terminal users.  A popup buffer 
>> could be an option, but if I had to choose between the two, I think I 
>> would choose the mode-line one, which is IMO less disturbing.
>
> And here is (a first draft of) the code for a popup buffer.
>

Two typos corrected.