How Much Longer Can RIM Keep Rallying?

Research In Motion (RIMM 1.26%), makers of the BlackBerry, are up more than 11% today, meaning it's up over 160% for the past six months. The market's reaction came on the heels of news that the company might spin off its handset business and switch to a licensing-based business model, which is a higher-margin space. In this video, Motley Fool tech and telecom analyst Andrew Tonner tells investors that this is old news, and that without having seen how Blackberry 10 will perform, or what the company's device shipment plans are once it launches, there is still plenty of risk here and investors should temper their optimism.