I am a new switcher to the Mac and within a few days I should be receiving my new iMac (listed below). I understand the book written by David Pogue "Mac OS X: The Missing Manual Tiger Edition" is available and highly recommended by several users for us switchers. However, with Leopard around the corner do you think it would be useful to purchase this book now and get used to the platform or wait until the Leopard edition comes out?