How about a way to flag potential duplicates when people import their GEDCOMS?
I just went on the entry for one of my ancestors and found that somebody had "added a child" who was a duplicate of an existing child. I keep running into those and it seems like it ought to be possible to cut down on confusion by sending the importer a list of potential duplicates when they upload the file. Maybe that's a pipe dream, but it would sure save a lot of time and annoyance. As it is, only people who are actively working on their trees see that "new people" have been added, and the errors accumulate.