According to the sources, TSMC is expected to enter the photomasking process; which is one of the final steps in the circuit design in March. So this means that the production will start in May or June. TSMC has set a budget of $9 billion for 2013 which is an increase of $700 million from the previous year and this shows that it is really working hard to complete the task given by Apple.
It is to be noted that Samsung was the biggest processor manufacturer to Apple but after the patent fights Apple is now moving towards other sources for its chip manufacturing.
We may not see this chip in the next generation iPhone or an iPad as the commercial shipment will not start before 2014. Apple is currently using A6 processor in iPhone 5 and iPad 4 which is built on a 32nm process.