Yes, such a plugin would be useful. I'd love to see it implemented in a way similar to newer MS Office version which provide such meta data (and ways to edit, too) via application menu (e. g. green "File" in Excel 2010) -> Information -> right half of the overlay dialog.
Regarding layer count: that's a nice workaround. But wouldn't it be nice to have a status bar, showing "Layers: X" - just next to already provided information like dimensions in pixels, current cursor position, unit, zoom level, etc.?
I apologize, if I didn't explain it correctly. I do know that PDN can't do it right now. However, I'd like to request that it can by submitting this request in order to get it onto the roadmap.
To say it clearly: thanks for providing those workarounds. I do appreciate your commitment/dedication, help and professionalism!
It's fine with me, if it's "down the list". All I'm asking for is to have it on that list - but unfortunately, what used to be PDN's roadmap, is more "changelog only" than "roadmap + changelog" nowadays. Maybe that could be improved, too?