As they do each year, Apple has announced that the iTunes Connect will be shutting down from December 23 through December 27 this year. The week long break is aimed to give App Store staff time off and for backend updates.
For those unfamiliar with it, iTunes Connect is the mechanism by which developers submit their apps to the App Store as well as any pricing or description changes. With it shut down, developers will not be able to submit any app updates, new apps to the App Store, pricing changes or any other changes. This process is in place so Apple can review apps and updates as they are submitted.