A deal between Apple and Verizon may take longer to materialize than normally assumed, says Kaufman analyst Shaw Wu. AT&T's exclusive hold on the American iPhone is expected to end in summer 2010, and Wu notes that adding Verizon to the list of carriers will open up a market of 89 million potential US customers, greater than AT&T's current 82 million. AT&T will likely push to have the contract extended into 2011, says Wu.