I am a TV journalist working for a German TV science and technology magazine show. Plus, I have been interested in the "Graf Zeppelin" for a while now.
Today, I talked to a naval historian who wrote a book on the carrier. He was 100% sure it is the "Graf Zeppelin". Later today, I called the Polish Navy's press office and asked them about their findings. There, I was told that they had a ROV (remotely operated vehicle) in the water at the wreck and also thoroughly inspected it using sonar. I got to see the sonar images and it is obvious that this is definately the carrier. Even in the low-res pics I got to see, it was very easy to make to a number of features like the plane elevators, the flight deck, flight deck artillery, etc.
I am currently working to get a dive expedition to the wreck started for our TV magazine, so I might actually be at the wreck filming with archaeologists and naval historians. Keep your fingers crossed that that will work out. I'd love to go there.