For the second time in as many trading days, shares of BlackBerry were halted in advance of some big news from the company. Today's news is no less big. BlackBerry has just announced that it's signed a letter of intent agreement for a sale of the company for $4.7 billion to a consortium led by Fairfax Financial (the company's largest shareholder). Pending due dilligence that's expected to be completed by November 4th
