We'd already heard that Windows Phone 7 is set to get an update of some sort early next year -- possibly coinciding with Mobile World Congress in February -- but ZD Net's Mary Jo Foley is now reporting that an even bigger update could be following in August or September. According to her sources, the update is codenamed "Mango," and it will effectively amount to Windows Phone 7.5, which she says might even be the actual name when it's released. 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. It will also presumably be the most significant update until Windows Phone 8, which Foley says is codenamed "Apollo," and is on track for a release in late 2012.

[Thanks, John]