AAPL is presently trading at 11.6x and EPS 2013/2014 of USD 43.20, which is about a 20 % discount to the US IT-hardware peer group.
The product launch of next month should be considered as a catalyst for unlocking further value to investors. Apple is financed in a very sound manner; the company holds about USD 130 billion of cash, pays a dividend of 2.6 % (which is higher than the average IT sector). With a successful launch of the new application, Apple could close rapidly the valuation cap, hence the stock could move into the region of USD 600.- which would imply a P/E of 14.5x.
Apple looks expensive the day you buy it, but it is inexpensive based on medium term potential and compared to the peer-group.