CLAMP-NET has updated with news that a Calendar 'Kisekae/Dress' app will be on sale for 350 yen at the iPhone app store starting April 15th. The app will allow you to change your calendar skin to feature one of 5 different CLAMP skins - Kobato., xxxHolic, Tsubasa, Magic Knight Rayearth, or Cardcaptor Sakura.
[credits: CLAMP-NET, Calendar Dress app website, Apple Japan]
Not sure if those overseas can buy apps from the Apple Japan app site.
Also noticed that Viz's 3-in-1 X manga is up for preorder at Amazon.com. Volume 1 will be out October 11th, and Volume 2 in January, 2012.