AT&T (T -2.5%) remains negative after reporting it sold 10M+ smartphones in Q4. One concern: smartphone subsidies will depress AT&T's Q4 margin, and since much of Ma Bell's base already owns a smartphone, the service revenue benefit might not be huge. Apple (AAPL +0.1%) has given up its early gains. With research firms having reported the iPhone is doing very well in the U.S relative to Europe/China, sales concerns mostly revolve around international markets. Meanwhile, Tim Cook is paying another visit to China - is he there to nail down an elusive China Mobile deal?