Microsoft Corporation (NASDAQ:MSFT) has announced that they have 15,000 registered Windows Phone 7 developers. As of right now, they have about 3,000 apps on their app store. Since September, the number of Windows Phone developers increased by about 80%.

Microsoft Mobile Platform Services Product Management Senior Director Todd Brix announced at the Microsoft Worldwide Partner Conference in New Orleans that the Windows Marketplace is on schedule for launching in 29 countries on July 27th.  As part of the launch Microsoft will be announcing some sort of contest around the time of launch.

The applications that will be available on the Windows Marketplace will be compatible on Windows Mobile 6.0 and Windows Mobile 6.1 devices.  There are about 30 million devices running those operating systems in the market today.

Some of the categories in the Windows Marketplace platform includes Books, Business Center, Communication, Reference, Entertainment, Games, and Lifestyle.

More details to follow on launch day on Pulse 2.

[via Windows Team Blog]