First cities are Atlanta, Chicago, Dallas, Houston and San Antonio; Ten more will follow later in the year
Reports have Google and Sprint unveiling the new system on Thursday
Microsoft names 3 more smartphone makers, says Mango-based phones coming in the fall
Users can upgrade after reaching limit or will see data speeds dropped to 2G
New video gives users quick way to track voice and data
One mega-data plan could cover smartphones and tablets
But AT&T warns not to project real-world speeds from its lab tests
Switch to digital books a turning point, as public transitions from paper books to e-readers
Trophy device set for sale at $150 on Verizon Web site on May 26, and in Verizon stores on June 2
