Microsoft has announced through its official Windows Phone blog that users of Windows Phone would not be able to buy or browse app using the Zune Desktop software from now onwards. The users will be notified of this change, the moment they will launch Zune Desktop on their computer system. Secondly, Microsoft has also made it mandatory for Windows Phone users to upgrade to Windows Phone 7.5 (Mango) or higher version to access and purchase new apps on the Windows Marketplace.
Since most Windows Phone 7 users buy and download apps through their phone or via the web store, having Windows Marketplace in a third location was unnecessary. This change is only for Windows Phone 7 mobiles as the Zune HD app store will continue to exist through the software. While this might not really affect most Windows Phone users, a more exciting announcement should have been the removal of Zune dependency all together for Windows Phone 7 devices.
This move could be an indication that Microsoft is preparing devices and the Windows Marketplace for a smooth transition to Windows Phone 8. The Windows Marketplace now features over 80,000 apps available in 54 countries and still counting.
Read the official Windows Phone blog post and know more in detail about the changes.