Apple broke with tradition when it declined to make the iPhone 5s available for pre-order after its announcement, and now it's looking like low stock might be the reason. According to All Things D, sources at the wireless carriers are claiming that launch inventory will be significantly less than expected. "We will have grotesquely unavailable inventory," said one carrier source, while another claimed that shipments from Apple were extremely disappointing. However, that same second source also said that demand for Apple's flagship iPhone might be less than anticipated, as well. Despite Apple's silence on iPhone 5c pre-sales, it seems that the company's new colored device is proving popular with customers so far, at least according to All Things D's sources. While there's no word on how the iPhone 5c may be selling so far, it appears Apple has enough devices to meet demand — you can still order one from Apple's site and get it delivered on launch day.

It's also looking like these availability issues might extend beyond the carrier stores: 9to5Mac is reporting that the iPhone 5s will be hard to come by at Apple's retail stores, as well. Out of all the shipments of new iPhones going to Apple stores, between 70 and 80 percent of the stock will be the iPhone 5c. Of course, there's also a chance that this report will just help to fuel the launch day mania for the iPhone 5s and build up those famous launch-day lines that have greeted all previous iPhone launches. We'll find out this Friday when both the iPhone 5s and 5c officially become available.