Walgreen (NYSE:WAG) on Tuesday said fourth-quarter earnings rose to $470 million, or 49 cents a share, from $436 million, or 44 cents, in the same period last year. Revenue rose to $16.9 billion from $15.7 billion. Excluding one-time charges, Walgreen said it earned 54 cents a share, while analysts polled were looking for earnings of 44 cents on average. In other news, Shares of Research in Motion (NASDAQ: RIMM ) were expected to be in the spotlight after the company late Monday unveiled a touch-screen tablet device called the BlackBerry PlayBook, making it the latest wireless-device maker to step into the new market. –Marketwatch In what could be a harbinger of a protracted retrenchment in Southern California’s defense industry, Northrop Grumman (NYSE:NOC) said Monday… . . . → Full Story: Market Updates: Walgreen (NYSE:WAG), Research in Motion (NASDAQ:RIMM), Northrop Grumman (NYSE:NOC), Ford Motor (NYSE:F)