Silhouette has now launched a new machine called the Cameo (it's 12 inches instead of 9!). They will no longer sell the Silhouette SD. Right now, they are on sale for $175 and they will go until they are gone. The supplies are limited, so if you want to get a Silhouette SD, don't wait. Use code SIMPLE. Also, all products are 20% off right now, use SIMPLE for that too.
There was some concern about Silhouette still selling the products for the Silhouette SD after it is discontinued. I contacted them and the company will still sell the mats and 9" products