Canaccord Genuity's Michael Walkley has raised the firm's price target for Apple stock from $515 to $545, citing "solid demand trends" for the iPad and iPhone. Checks are said to show that high June-quarter iPhone sales persisted into the month of August, leaving the iPhone 4 as the bestselling smartphone at both AT&T and Verizon, despite growing competition from Android and public expectations that a new iPhone will launch shortly. "While our August checks indicated improving battery performance for 4G/LTE/HSPA+ Android smartphones at several carriers, these devic