Today the Cocos2d-x community released the v2.0 version of Cocos2d-x for Windows Phone 8.
Note that it is the first version for wp8 which has v2.x API set migrated, this has been a cooperation between the Open Source community Microsoft and Nokia
Download link: Cocos2dx-2.1.0-wp8-2.0-alpha.zip Github repo: https://github.com/cocos2d-x/cocos2dx-win8/tree/wp8_v2
This branch of Cocos2d-x uses Direct X 11 for rendering while still uses C++ to program, with the same API as Cocos2d-x v2.1.
There are already many games in the pipeline and scheduled to be available soon in Windows Phone Store, using Cocos2d-x WP8 2.0.
Work is also well under way for a Cocos2D layer on top of MonoGame see https://github.com/mono/cocos2d-xna