Amazon is buying 767’s...How might that affect FedEx?
Could the on-line giant eventually compete on an even footing?...
Clearly Amazon controls very little ramp space at congested airports both domestically and internationally, nor the infrastructure to sort and distribute millions of packages daily without the USPS, FedEx, and UPS.

However after looking at the financials there might be something else to consider:

FedEx Corporation enterprise value: 68.7 Billion dollars
Enterprise Value = (total company value)

Amazon Corporation enterprise value: 562 Billion dollars
Amazon CEO Jeff Bezos net worth: 98 Billion

Jeff Bezos personally has more net worth than the total value of FedEx. Clearly there are a number of variables, however if you wanted to expand the Amazon airport ramp presence both domestically and internationally, control of the largest wide body fleet of aircraft in the world, and FedEx Office services it seems reasonable that FedEx could be considered low hanging fruit.