iTunes Connect is the portal for developers to submit app updates and changes. As a result, no new apps, app updates or price changes will be reflected in the App Store during that time.
As a result of the shutdown deadline, a large number of App developers have been cutting prices today as they compete for top ranking on the App Store Top Charts during the lucrative Christmas sales period.We strongly recommend that you do not schedule any pricing changes in iTunes Connect that would take effect between Friday, December 21, 2012 and Friday, December 28, 2012. Pricing changes scheduled to take effect during this date range will not be reflected on the App Store and your app or In-App Purchase will become unavailable for purchase until after the shutdown.
We also recommend that you do not schedule any apps to go live during the shutdown. Releases scheduled with a start date between Friday, December 21, 2012 and Friday, December 28, 2012 will not go live on the App Store until after the shutdown.
Article Link: Apple Reminds Developers of App Store Freeze During Holidays