Microsoft confirmed today that some Xbox One systems are facing a hardware issue that makes the console abnormally loud right out of the box. The good news is that the issue is limited (only a "small number" of systems are affected) and if you do have a noisy console, you can get a replacement. It's a bummer if you have an affected console, but hardware issues do happen.
"We have heard that a small number of Xbox One owners in some situations may hear a noise from the console that is too loud," a Microsoft representative confirmed with GameSpot following the initial report from Kotaku. "While this does not affect the safety or functionality of the system, we're asking customers who believe they are experiencing this issue to contact Xbox Support: http://support.xbox.com. At the request of our customers, we are exchanging those consoles for new systems."
September is a major expansion month for the Xbox One in terms of worldwide availability. The console hit Chile and Colombia on September 2, Japan on September 4, and sixteen new countries on September 5, including Poland, Portugal, Sweden, and Greece. The Xbox One launches in Israel on September 25, and major markets like China (September 23) and Russia (September 26) later this month.