Turning @Shog9's original idea into a feature request:
The way duplicates are handled should be revamped. When a 3k+ user votes to close a question as a duplicate, instead of a "possible duplicate" comment or the new banner showing up, the system should automatically generate an answer containing the duplicate link.
It could look like this:
The answer would be special in that:
It's visually distinguished from other answers, eg. through a lightly coloured background
It cannot be edited (or maybe it can, it's a detail that would have to be discussed)
It can be voted on by the community, but doesn't generate rep (= auto-CW); the voting doesn't influence the closing process
It has a "confirm" button to the right that allows other 3k+ users to check out the suggestion, and either agree or disagree with it (a shortcut to the "vote to close" dialog, which would stay in place). Agreeing gives the post a +1, disagreeing a -1
If the OP marks a suggested-dupe answer as accepted, the question gets automatically closed as a duplicate.
Five 3k+ users disagreeing with a dupe suggestion automatically reopens the question
This would not change the existing "vote to close" process. It would still take five 3k+ users's close votes to close the question as a duplicate. However, the whole community can cast a vote on the suggestion and hence express its agreement or disagreement with it. Every new dupe suggestion becomes an answer of its own, and can be discussed separately.
Clicking Confirm or upvoting as a 3k+ user automatically brings up the confirmation dialog containing the suggested dupe. There is no dupe-voting without having to actually check out the suggestion. This part of the process does not change.
This is cool for a plentitude of reasons:
Dupe suggestions get a lot more exposure this way, instead of being hidden behind
The entire community gets to participate in the process - everyone can vote (and hence provide pointers to closevoters which one is the best suggestion) and comment on the suggestions, which increases everyone's incentive to verify them.
The fact that there is a possible duplicate becomes even more prominent than with the new banner, but in a less obtrusive way
People currently composing an answer are notified of the suggestion (because it's a normal answer) and can check it out. If they find the dupe provides good answers, they can stop wasting their time, or consider answering the original instead
Users who find the duplicate get the recognition they deserve
Votes on these pseudo-answers introduce a new metric of citizenship. A high number of dupe suggestions that were confirmed by 4 other users is one good indicator that you're a good citizen
OPs can accept a dupe suggestion, which adds an additional signal that there is another place that has great answers for future generations of Googlers.
Multiple duplicate suggestions become trivially easy to handle and discuss separately.
This will feel much nicer for non-3k users. Until now, to the normal user, the closing process feels like something a cabal of 3k+ users prepares in secret, until the edict comes down. This way, a dupe suggestion becomes a contender for the public vote just as any other answer.
There is a "lite" version of this request now: Create CW answer for every "Vote to close as duplicate" vote