I have experienced the same issue. I dont think it should do it. No screen should have a ghost image after a short period of time unless its a plasma.
Im going to take mine back to the apple store when i return from overseas for work.
I had this same thing happen a year ago with the iPad 2 model. The unit was used a little bit and then when I opened the app Pulse, which has a solid gray background, I could see the silhouette of the search bar for safari, and the header for my email Apps still there. I tried the same thing but in a different orientation and after a few minutes of usage the ghost image would be in the new position.
If you are getting this, take it back now as it only will get worse. When I was at the Apple store looking at the new Retina MBP I wanted to buy one very badly. However, I remembered the first run of some ot the last Apple products I purchased and how those products faired. Try another one and if you don't see improvement, I'd just hold out for the next generation they release next year and let the kinks get ironed out. The initial concern with Apple always seems to be get as many units out to the customer and quality will come in time once production is ramped back down.