The latest indicator is the most recent release of the Microprocessor Report, in which Linley Gwennap argues that several hundred million dollars of investment are paying off for Apple. The latest A6 processor design is recognized as unique and as a design "that has never been seen before." That indicates a design that is specifically tailored to the needs of the iPhone and the iPad, which makes economic sense at the scale of current iPhone and iPad shipments.
Gwennap notes "that the iPhone 5 could generate $20 billion in revenue" in the Christmas season alone. "So that half a billion dollars [of investment] could be money well spent," he said.
However, Apple appears to be now reaping the fruits of its gutsy move to develop its own microprocessor with the help of acquired companies such as PA Semi in 2008 and Intrinsity in 2010. There was the notion that Apple could never compete with the processor design resources by companies such as Samsung or Intel, but it seems that the company is changing opinions.