iPhone 5 and Keynesian Economics

Analysts at JP Morgan released a report that argues that Apple's release of the iPhone 5 could potentially increase GDP growth in Q4 by 1/4-1/2 percentage points.

How?!?
1. The report projected that, given last year's 4S sales, Apple will sell an enormous amount of phones in the 4th quarter, given the fact that the iPhone 5 launch is expected to be bigger.
2. Although iPhones are manufactured overseas, the majority of the price you pay is domestic value-added (retail, advertising, profits).

Is the JP Morgan report convincing? If so, what does it say about the state of the U.S. economy?

Krugman is calling it "The iPhone Stimulus"