Blame Oprah.Or thank her - it all depends on whether you're buying or selling Amazon.com's (AMZN) Kindle e-book reader.The online retailer thought it had enough of the gizmos in stock for the Christmas season but Ms. Winfrey flexed her marketing muscle on her nationally televised show by proclaiming the e-book reader her "favorite new gadget." That created a stampede of buyers. The device is now out of stock and a new supply won't arrive until February the Wall Street Journal reports.Yawns greeted the Kindle when it was introduced last year. The device is expensive -- now $359 but $399 last ...