AT&T (NYSE:T) mobile chief Ralph de la Vega says his company will try to lower smartphone subsidies this year in order to reduce their margin impact. Ma Bell's efforts to eliminate early upgrades already contributed to a 41% Q/Q drop in smartphone sales in Q1. Worries about iPhone subsidy cuts at AT&T and elsewhere have weighed on Apple (NASDAQ:AAPL) shares - the $350+ retail subsidies often given for the iPhone are among the industry's highest.