Aِccording to Engadget Microsoft is planing and working for the next updates for the Windows Phone. The next major update, called “Mango” will be available next August. Its commercial name might be Windows Phone 7.5. That update will apparently bring Silverlight runtime and HTML5 support to the OS, along with Far Eastern language support, and some other unspecified features and functionality.
Engadget source mentioned a new version of Windows Phone, with code name “Apollo” that might come late by 2012 with commercial name Windows Phone 8.