The US Patent and Trademark Office issued Apple a design patent on rectangular devices with rounded corners.
Patent no. D670,286 pertains to the "ornamental" design of the iPad, and essentially covers a "Portable display device" that's a rounded rectangle. While it will cover Apple's claims to innovating such a design, the usefulness of such a vastly broad patent is questionable.
As can be seen in the picture above, particular focus is drawn to singlular solid line around the rectangular shape of the iPad, whereas the rest of the more faintly illustrated details of the tablet are just present for context. It clearly demonstrates the purpose of providing coverage on this specific aspect of the design. This makes for an extremely broad, almost vague design patent, meaning it is easier judge, jury, or Patent office to battle and invalidate accused infringements.
Simply put, without specific details, a patent of a rounded rectangle may not hold up in court. Will this be brought up in the courts, and how effective will it be? We'll see what happens, if and when Apple make use of their newly attained patent. Maybe it won't stand a chance like their previous passage through the British courts against Samsung.