The company has informed us today that it has successfully fixed the issue and developers can start submitting their apps again. Those developers, whose apps were caught in the middle of the publishing process when the problem occurred, do not need to resubmit their products.
Windows Phone users should keep in mind that it might take a day or two before Microsoft's fix is fully deployed and new apps start popping up in the Marketplace.
Windows Phone has been having a hard time catching up to iOS and Android ever since its launch, but it has made quite a bit of progress, already having a large catalog of apps and a vast overhaul coming soon in the form of Windows Phone 8. The first WP8 devices are expected to be announced as soon as September 5, when Microsoft and its biggest hardware partner, Nokia, will be holding an event in NYC.
source: WindowsTeamBlog via Engadget