New Apple CEO Tim Cook previewed an improved iPhone 4S, with new "Siri" voice recognition technology and a better camera, says the San Jose Mercury News. But despite the speculation, Cook didn't show off a next-generation iPhone 5, and that was bad for Apple stock ("AAPL"). The upgraded 4S sports a faster processor and can run on phone systems outside the U.S. But it looks just like the current iPhone 4 model, available in either white or black. Apple has expanded its range of partners, adding Sprint to current wireless partners AT&T and Verizon. The new iPhone 4S will be in stores Saturday, October 15. The previously announced iOS5 mobile operating system is available October 12, the same day the "iCloud" debuts.