Recent mercurial versions mark "modified" subrepos (modified in the sense that a revision was added or modified). We should be able to use that to implement this feature. Or we could check if we are in a subrepo when we commit and in that case highlight the subrepo in the Repository Registry.
Detecting a dirty working directory would be harder without doing some sort of polling.
I don't see a lot of value to this myself, but I can see how it might be useful for others. Would we simply mark the "modified" repos somehow (perhaps with a different color or font type) or would we need to show the number of changes in the repo registry?
Any progress? It is very annoying to check every single repository in the registry from tens to uncommited/unpushed changes. You have similar functionality for Windows Explorer, but the projects is not in one folder, so it is not a case for me :(