After being listed on its online sales portal with no official announcement last week, AT&T has officially confirmed that it will launch the Samsung Galaxy S IV on April 27th in-store, with pre-orders shipping two days earlier on the 25th. The phone will be offered in 16GB and 32GB versions in both black and white for $199.99 and $249.99 respectively. The phone features a 5-inch AMOLED display ..