Two weeks since its launch, the iPhone 5 continues to be in “extremely limited” supply in Apple Stores. Piper Jaffray surveyed 100 Apple Stores in the US over the last week and found so few devices that it decided to lop off more than 2 million unites from its September iPhone sales forecast. Estimated shipping times for online orders remain at 3 to 4 weeks. [Source: AllThingsD]