This has happened to me twice, the first time was about 6 weeks ago... I took it in with the "eyelid" almost half way down (the camera wasn't affected, but it looked bad) and the genius said it was the first time he had seen it. He then took it back and actually pushed it back up or something like that. And then last week I noticed it was drooping again so I took it in again yesterday and explained it, saying it was the second time. The genius then said I had two options, replace just the camera or get a "new" one so I just took the new one knowing I had a ding on the top (I didn't want him messing with my camera anyways so it wasn't me intentionally trying to get a new one).
Thanks, Scheduled my Genius bar appointment for Thursday. Another person posted a thread about it that I got a link to, he said Apple gave him a new phone and told them that the seal/glue must have failed causing that piece to shift down like that.
Suffering this with my phone; its preventing the camera from focusing on anything less than 2m away (i.e. scanning barcodes) - taking mine to a genius on Monday