AT&T could see a large portion of its smartphone subscriber base jump ship for the Verizon iPhone next month, a study found on Thursday. Of those asked by ChangeWave, 15 percent of AT&T subscribers said in December they were likely to change carriers in the next three months. While not an indicator in itself, it mapped almost exactly to the 16 percent of customers who said at the time that they would switch if Verizon had the iPhone.
