Apple has informed developers about the closer fo Mac OS X website on January 6th:
Thank you for making the Mac OS X Download site a great destination with apps that offer users new ways to work, play, learn, and create on their Mac. We recently announced that on January 6, 2011, the Mac App Store will open to users around the world, presenting you with an exciting, new opportunity to reach millions of customers.
Since the introduction of the App Store in 2008, we've been thrilled with the incredible support from developers and the enthusiastic response from users. Now we're bringing the revolutionary experience of the App Store to Mac OS X. Because we believe the Mac App Store will be the best destination for users to discover, purchase, and download your apps, we'll no longer offer apps on the Mac OS X Downloads site. Instead, beginning January 6, we'll be directing users to explore the range of apps available on the Mac App Store.
We appreciate your support of the Mac platform and hope you'll take advantage of this new opportunity to showcase your apps to even more users. To learn how you can offer your apps on the Mac App Store, visit the Apple Developer website at http://developer.apple.com/programs/mac/.