Answer to "Is it possible to replace the DVD with a blu-ray drive?"I believe the answer above is wrong. I am adding this in case someone else wonders. My 2010 iMac certainly required a 12.7mm drive which I have fitted. It's the Macbook Pro that requires a 9.5mm drive. There are many more options for slot-ins here, both Blu Ray burners and players, UJ265 from Panasonic is what I went for.