Steve Jobs may have left the building, but his love of patents remains with Apple. The company recently patented its MacBook Air wedge design, making it nearly impossible for competitors to be just that: competitors, at least in the field of ultra-thin notebooks.
A design patent doesn't only disallow identical products. It actually disallows products that are even similar to the design. A panel of judges decide if a product is too similar, but this effectively means you'll be turning to Apple for all your ultra-thin notebook needs.
The patent last for fourteen years, after which any Tom, Dick and Harry out there can go ahead and make a MacBook Air.