Apple's New Advantage: Silicon
It looks like Anand misspoke. The A6, he now believes, is not a Cortex A15, but a custom ARMv7.
A lot of people, including myself, were wrong in assuming that Anand had insider info. We can't be entirely certain until the 21st, but I would like to run with the idea of a custom ARMv7 design.
Apple has been hiring a lot of talent from many parts of the ARM chip manufacturing industry and from x86 manufacturers like AMD and Intel. For the past several years, Apple has just been content with licensing the core (A8, A9), while other companies like Qualcomm licensed the instruction set (ARMv7 in the S4).
Now, it seems that Apple wants to take much more control and license the IS to build their own custom cores. With the custom cores Apple can really change things to their liking.
The benefits of the custom design include being able to focus on energy efficiency and being able to better integrate it with their software. Apple's A6 is a first attempt at trying to create their custom core, so it may not blow people away, but like the advance from the A4 to the A5, expect the A7 to be amazing efficient and powerful and really showcase the work Apple is doing.
In a sense, this is a step to owning the whole widget (vertical integration), which would give them an advantage, like their supply chain. I await the day when everything inside an iPhone is Apple designed. They design the SoC, they are closing in on SSD (Israeli firm they purchased), the manufacturing process, the screen (as shown with the iPad 3 and RMBP, yes they do design displays), and the software in addition to other smaller pieces. What they are missing is really only designing RAM, GPU, and the cameras. Expect them in the future to design those as well.
The new silicon is just one more thing on the list of Apple advantages.