AT&T issued new financial guidance, saying cost synergies from its recently completed merger are ahead of expectations and power double-digit adjusted earnings per share growth and strong cash flow growth over the next three years.The company said the net present value of AT&T merger synergies is now expected to be approximately $18 billion, versus its January 2005 estimate of $15 billion. AT&T now expects total synergies from the merger to reach an annual run-rate approaching $3 billion in 2008. Overall integration costs are largely...