Pre-orders for The White Light of Tomorrow are now live at Amazon and Smashwords. Over the next few hours, the book should become available at Apple, Barnes & Noble, and most other ebook retailers. A paperback version will also be available through Amazon on or about May 1. Keep an eye out here and on my Facebook page as there are sure to be some promotions in the lead-up to the official release!
Edit: Now available from Apple, too!
Edit: Here are some Amazon links from around the world: