Duplicates now have the following message above them: "This question already has an answer here", where previously the message was "Possible duplicate" (see this meta question).
The current message is much stronger in the sense that it indicates 1) it certainly is a duplicate and 2) it certainly has an answer to your question.
I do see the high probability of a question actually being a duplicate if many people indicate it may be so. And even if this is not the case, you can appeal and users are notified about the options (albeit this could be improved).
However, the second claim by the message (there certainly is an answer), is not necessarily true. To clarify I'll refer to my case: I recognise that there's a duplicate, but the answers provided at the 'original question' do not help me. Although the question asked was desktop environment-neutral, one of the answers is not. The other answer is a work-around solution. I imagine quite a portion of the users don't find an exact & directly applicable answer to their problem in the original (non-duplicate) question.
The issue here is that the duplicate message might set wrong expectations. When faced (esp. as a novel user) with a duplicate message, you'll go look at that question, expecting to find a solution to your question (that's what the message says, after all). Possibly you won't. If that's the case, this may lead to frustration. Especially as "most OP's feel bad to ask a duplicated question" (@Sneetsher) the negative feeling about self could turn into negative feeling about this false claim (an answer being available).
To 1) exclude the possibility that the duplication message is false (ie there is no answer to the person's question whilst is says there is) and 2) to lower the risk of user frustration in this process (which for the user most likely already is a negative experience), I'd propose a change from "This question already has an answer here" to "This question might/likely already have/has an answer here"
PS. Of course the message says 'an answer', rather than 'the answer', but I guess most users would read it as 'the answer to your question already is here'.