Another option would be for Apple to use BluetoothLowEnergy for payments and Apple has already included those chips in the iPhone 4s, but more on that another time.
Our PSoC products are well suited for Bluetoothlowenergy applications in this market, as their programmable analog and digital peripherals can interface with almost any sensor to provide integrated one-chip solutions to our customers.
The watch is powered by a regular button cell, but thanks to the low-energy design, the watch can go two years between battery changes, assuming that the Bluetooth function is used for about 12 hours per day.