IDC analyst Francisco Jeronimo asserts Nokia's attempted U.S. comeback is threatened by the Finnish phone-maker's failure to produce a 5-inch smartphone. The company's flagship Lumia device tops out at 4.5 inches. Jeronimo predicts Nokia will release its own large-screen handset within a few months. "People are using smartphones in different ways now, consuming media by streaming over faster mobile networks. A 5-inch screen for a smartphone just feels right in the hand," Jeronimo says.