"We believe Apple is looking to merge iOS (iPhones/iPads) with OS X (Macs) into a single platform for apps and cloud services starting in 2012-13," Jefferies writes. "Our preliminary view is that Apple can use a 32-bit ARM architecture to address the vast majority of the OS X ecosystem's needs in 2012-13 except for high-end professional devices. When 64-bit ARM is available in 2016, we believe Apple will have a single OS and hardware architecture."

While the iPad 2 uses the Apple A5 chip with a dual-core ARM processor, Jefferies speculates that "Apple is ready to start sampling the A6 quad-core app processor and will be the first such multi-device platform capable of PC-like strength."

Jefferies predicts the iPad 3 will launch with the A6 chip in Q1 2012, while an A6-powered iPhone will launch next summer. The MacBook Air will get the A6 in the second half of 2012 or in 2013, but the higher-powered MacBook Pro laptops and Mac desktops will stick with 64-bit Intel chips until 2016, the analyst firm says. 64-bit chips allow greater use of memory and are useful for "computationally-intensive programs like Adobe's Creative Suite."

Apple to have one OS for Macs and iPads by 2016