AT&T wireless chief Ralph de la Vega at the Morgan Stanley Technology, Media and Telecommunications conference in San Francisco today said the company wasn't alarmed at the impact of the Verizon iPhone 4 launch. He declined to get into numbers but said the number of AT&T subscribers jumping ship for Verizon was "within our expectations." The carrier hadn't "seen any surprises" in the first two weeks, de la Vega said, although he admitted that numbers were in flux and that the trend might change later.