There is the good old Cartographer_QuestObjectives, which is working quite good; but I'm afraid it'll die with Wrath (no, I didn't test it yet, but I'm planning it.) and I hate to lose my data. So if a conversion can be made for HandyNotes, with an import function from the old Cart module... that would be very nice :)
While I don't think such an idea is bad from the offset, I think the original Cartographer approach was flawed in practice. How could we improve upon that?
One approach is that we could base the information on WoWHead dumps, like LightHeaded does. The upside of this is that it would reduce map clutter, it wouldn't try to note where every wandering mob is, so you wouldn't end up with some kind of World Map cancer (which was my problem with QuestObjectives). You'd only one one general pointer of an area where you should go to.
So what I'm suggesting is that the new idea wouldn't manually detect quest objectives, but it would come with a pre-built database.
Do I think it's a good idea? Possibly, for those who don't find LightHeaded intuitive enough.
Do I think I could do it? Hell no. I have as big of an attention dysfunction disorder as Deadpool, therefore it would all go horribly wrong. It would take a coder with great amounts of both skill and patience.
I was thinking about that yesterday (and don't forget this old thread too), and I'm thinking I was wrong, we don't need a HandyNotes_QuestObjectives addon. The original Cart_QO is a gathering addon, not a note-like thing; so the replacement should be a GatherMate-plugin... :)