Putting magnets that strong inside of an all in one computer is not a wise idea. I don't think it's held in place with magnets. Also, if they are strong enough to hold the remote, I think someone would have noticed. Also, didn't the remote have a magnet inside of it in order to stick to the magnet inside the imac? If so, the new remotes probably don't have that magnet in them since there is no place intended on the new imac to put the remote. Especially considering that Steve Jobs would have mentioned the remote sticking to the imac in the conference he had.
Engadget has a nice thread on this, referring to the Kodawarisan site. They seem firmly convinced that magnets are used, and that they would not cause problems with the HDD, etc.
What I want to know is whether the VESA adapter for the 2005 G5 iMacs can be attached to these, similar to what was discovered for the 2006 intel iMacs. It would require tearing down the computer to get to the boot hinge, which could be a bit daunting, but if so it provides those who need to mount the computer on LCD arms the option of upgrading to the newer iMacs.
PowerSupport makes an anti-glare film for the macbooks; its support to cut down glare from lights and such. Don't know if it turns the screen matte but something like this could help for people worried about overhead lights.