I think some sort of flair like feature for marking posts as questions and marking accepted or best answers as such are missing. Flairs are desire anyway. Tags perhaps as well.
Then, if there are to be “super votes”, such as the OP accepting an answer or even a moderator highlighting an answer, that would be new too.
If the UI can communicate with a plug-in, I’d imagine that could all be plugin side.
what is the situation ATM for plugins affecting the UI in custom ways?
But yea, this seems like maybe a perfect test case for the plug-in system.