Yeah, it sounds like they're just trying to protect the concept of the iMac.
Scruffy, the patent system is really coming to the public eye in recent months. I know that various computer companies have patented progress bars, tabbed preferences, the "OK" button, buying with credit cards on the Internet, even the idea to "share files over a network" is patented. It is becoming quite a tedious problem and a minefield for anyone who wants to release any product of any kind.