The iPhone 5 comes with a brand new Apple-designed A6 chip for a twofold jump in CPU/GPU performance. In fact, the iPhone 5 could easily be the first ARM Cortex-A15 smartphone on the market. The A6 is likely manufactured on Samsung's 32-nanometer process, but probably not for long as Apple has been looking to take its chip contract elsewhere.
There ain't many places to go: Intel sucks at power management and Samsung is #2 chip vendor in the world. Taiwan Semiconductor Manufacturing Company (TSMC), however, is the world's largest dedicated independent semiconductor foundry and Apple could be closer than previously thought to shifting production contracts away from Samsung and towards TSMC.
Can you say "stock plunge"?