The Lumia 520 has already launched in the United Kingdom and other markets. It features a 4-inch WVGA display, a 1GHz dual-core processor, and a 5-megapixel camera. But most importantly it comes with Nokia’s free HERE Maps with offline navigation and the Nokia Music app with the Mix Radio free music streaming service.
The Lumia 520 sold at Expansys will work with AT&T and T-Mobile in the United States, but it is fully unlocked and not carrier branded. T-Mobile has announced it will bring the Lumia 521 in May. The Lumia 521 a very similar model that you’d be able to purchase with a subsidy on the carrier.