The iPhone 5 will be released in the fall, and it could come with a quad-core processor.
According to latest rumors, the future device will have a quad-core processor, similar to the Samsung Series 4 Exynos.
However, there is no info about the company that would produce these processors.
So far Apple used ARM processors, specially modified to function with these devices, and Samsung has been chosen for their assembly.
Whether the iPhone 5 features a quad-core processor will be clear in the fall. Until then this information should be taken as a rumor.