I'd be quite interested to have a go at this.
A simple plug-in displaying information about the currently playing track using the MJPlaybackAutomation server would be pretty straightforward, but is a long way from doing everything you want. It would be possible to go slightly further using MJCurPlaylistAutomation, but would limit browsing to the current playlist.
I believe that the best way to do things would be to have an iMon plug-in which works in conjunction with the Theatre View, since the navigation concept of Theatre View can probably be reproduced on the small iMon display.
To do this, I would need to have a mechanism to find out the current menu contents. The idea, I think, would be something like:
On the lower line of the display, the current menu item would be displayed in the centre, with as much additional text from the previous and next items as possible given the 16 character display limitation.
On the upper line would be a similar display for the previous menu, giving the user a view of what would be seen by pressing the 'back' button.
Anyone have any ideas how I could obtain information about the currently displayed menu? I can't immediately see how to do this, although MJViewItemAutomation looks as though it may be promising.
If there's a suitable mechanism for doing something like the above, I'll start to think about how the UI could look. Options are limited with a 2 x 16 display, but I'm sure that something should be possible.