THE PORTAL OF NEWS RELEATED TO NOKIA
Metro^7 is a custom Lumia 710 ROM built on the Tango release, and is now available over at the XDA developer forum. The author, XDA member vova1609, states that you need to have your Lumia 710 interop unlocked, but then you should be good to go with flashing.
Some highlighted features:
As well as the ROM and included functionality, an exclusive pack of ‘metro ROCK’ wallpapers are included, featuring multiple designs to match the system theme. Please note that Windows Phone Central does not take any responsibility for any issues your device may develop using this (or any other) available ROM. Use at your own discretion.