hello mosesjoy, i know of no ongoing development or efforts by mozilla of porting firefox to the windows phone platform.
originally there have been technical and legal hurdles in the app store which discouraged mozilla from starting any developments in this direction. i don't know about the current situation, but since mozilla is now focusing its energies on creating firefox os as open source web-based platform, i doubt that you will see firefox on your windows phone device in the foreseeable future...

The only mobile Firefox Mozilla is currently working on is for Android 2.2+.

There are no plans to make Firefox for any version of mobile Windows OS, with a big reason due to restrictions by Microsoft.