Microsoft has officially opened the Windows Phone 7 "Mango" marketplace for developer submissions today, opening the doors to applications with new capabilities such as utilizing the augmented reality API's, enabling multitasking and more. The marketplace is the "final" Mango marketplace and reflects what users will see when Microsoft makes available Mango to retail devices, as well as new hardware.
Previously, developers have only been able to unleash their Mango enabled applications by either distributing the XAP files or through the new private beta feature in the marketplace. To be able to submit their applications, developers are required to download another update to the WP7 SDK tools, which weighs in at a few hundred megabytes. According to Microsoft, developers can't submit apps without the new tools as they are missing a "Go Live" license that enables publishing in the marketplace.
Over the next few weeks we should see a slew of new applications, with support for the new features. Currently, phones with the Mango beta bits on them haven't got too many applications to actually use multitasking with, as it has to be enabled by the developer first.
The updated tools -- which include a "Go Live" license -- are available for download here. It's worth noting that if you have the older bits installed on your computer, you're required to remove them first.
Update #2: Uh oh. Chris Walsh notes that you can't update NoDo apps after you submit Mango apps.
Update #3: The marketplace is open for submissions now!